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Current view: top level - fft - rfft.f90 (source / functions) Hit Total Coverage
Test: FLEUR test coverage Lines: 0 865 0.0 %
Date: 2024-05-15 04:28:08 Functions: 0 14 0.0 %

          Line data    Source code
       1             : !--------------------------------------------------------------------------------
       2             : ! Copyright (c) 2016 Peter Grünberg Institut, Forschungszentrum Jülich, Germany
       3             : ! This file is part of FLEUR and available as free software under the conditions
       4             : ! of the MIT license as expressed in the LICENSE file in more detail.
       5             : !--------------------------------------------------------------------------------
       6             : 
       7             : MODULE m_rfft
       8             :    use m_juDFT
       9             :    PRIVATE
      10             : ! module also contains routines vrffti,vrfftf&vrfftb as private routines below
      11             :    PUBLIC rfft
      12             : CONTAINS
      13           0 :    SUBROUTINE rfft( &
      14             :       isn,n1d,n2d,n3d,n1,n2,n3, &
      15           0 :       nw1,nw2,nw3,wsave,b, &
      16           0 :       a)
      17             : ! **********************************************************************
      18             : 
      19             : ! isn = +1 : FFT a real, 3dim array "a" of dimensions n1*n2*n3 to a complex
      20             : !            array of size n1*n2*(n3+1)/2 [if n3 is odd] or n1*n2*(n3/2+1)
      21             : !            [n3 is even].
      22             : ! isn = -1 : back-FFT of a complex array "a" of size n1*n2*(n3+1)/2 [odd]
      23             : !            or n1*n2*(n3/2+1) [even] to a real, 3dim array
      24             : 
      25             : ! the actual array is assumed to be located between
      26             : !                                  1 ... nw1+1    &     n1-nw1+1 ... n1
      27             : !                                  1 ... nw2+1    &     n2-nw2+1 ... n2
      28             : !                                  1 ... nw3+1    &     n3-nw3+1 ... n3
      29             : ! and padded with zeros in between.
      30             : ! if nw1 >= (n1-1)/2, no padding is assumed (-> aliasing errors!)
      31             : 
      32             : !                                                  G.Bihlmayer (UniWien)
      33             : 
      34             : ! **********************************************************************
      35             :       USE m_constants
      36             :       USE m_cfft
      37             :       IMPLICIT NONE
      38             : 
      39             :       INTEGER :: n1d,n2d,n3d,n1,n2,n3,nw1,nw2,nw3,isn
      40             :       REAL :: a(n1d,n2d,0:n3d),b(n1d,n2d,n3d),wsave(n3d+15)
      41             : 
      42             :       INTEGER :: i1,i2,i3,nup
      43             :       REAL :: factor
      44             :       LOGICAL :: l_nopad
      45             : 
      46             : ! a ... array for FFT
      47             : ! b ... work array
      48             : ! wsave ... stores tables for r-2-c FFT
      49             : ! n1,n2,n3 ... dimensions to be transformed
      50             : ! nw1,nw2,nw3 ... actual dimensions of a before FFT
      51             : ! n1d,n2d,n3d ... dimensions of a,b
      52             : 
      53             : ! check for input errors
      54             : 
      55           0 :       IF ((isn/=-1) .AND. (isn /= 1))  CALL juDFT_error("choose isn=+/- 1" &
      56           0 :                                                         ,calledby ="rfft")
      57           0 :       IF ((n1d < n1) .OR. (n2d < n2) .OR. (n3d < n3)) THEN
      58           0 :          WRITE (oUnit,*) 'n1d,n2d,n3d =',n1d,n2d,n3d
      59           0 :          WRITE (oUnit,*) 'n1 ,n2 ,n3  =',n1 ,n2 ,n3
      60           0 :          CALL juDFT_error("n(i) > n(i)d",calledby ="rfft")
      61             :       ENDIF
      62             :       IF ((n1 <= 2*nw1+1) .OR. &
      63           0 :           (n2 <= 2*nw2+1) .OR. &
      64             :           (n3 <= 2*nw3+1)) THEN
      65             :          !        WRITE (oUnit,*) 'n1 ,n2 ,n3  =',n1 ,n2 ,n3
      66             :          !        WRITE (oUnit,*) 'nw1,nw2,nw3 =',nw1,nw2,nw3
      67             :          l_nopad= .TRUE.
      68             :       ELSE
      69           0 :          l_nopad= .FALSE.
      70             :       ENDIF
      71             : 
      72             : ! ******************** f o r w a r d - t r a n s f o r m *******************
      73             : 
      74           0 :       IF (isn == 1) THEN
      75             : 
      76             :          ! array a is assumed to be zero from (1,1,0) to (n1d,n2d,0) and the array
      77             :          ! to be FFT'd starts at (1,1,1) as n1*n2*n3 real numbers.
      78             :          ! first transform n1*n2 real sequences of lenghth n3 to n3/2 complex values
      79             : 
      80           0 :          CALL vrffti(n3,wsave)
      81           0 :          IF (l_nopad) THEN
      82           0 :             CALL vrfftf(n1*n2,n3,a(1,1,1),b,n1d*n2d,wsave)
      83             :          ELSE
      84           0 :             DO i2=1,nw2+1
      85           0 :                CALL vrfftf(nw1+1,n3,a(1,i2,1),b,n1d*n2d,wsave)
      86           0 :                CALL vrfftf(nw1  ,n3,a(n1-nw1+1,i2,1),b,n1d*n2d,wsave)
      87             :             ENDDO
      88           0 :             DO i2=n2-nw2+1,n2
      89           0 :                CALL vrfftf(nw1+1,n3,a(1,i2,1),b,n1d*n2d,wsave)
      90           0 :                CALL vrfftf(nw1  ,n3,a(n1-nw1+1,i2,1),b,n1d*n2d,wsave)
      91             :             ENDDO
      92             :          ENDIF
      93             : 
      94             :          ! now we have the FFT'd array stored as described in vrfftf
      95             :          ! (mixed real & compex data)
      96             :          ! remove the norm 1/sqrt(n3) (to be compatible with cfft)
      97             : 
      98           0 :          factor = sqrt(1.0*n3)
      99             :          ! ALL CPP_BLAS_sscal(n1d*n2d*n3,factor,a(1,1,1),1)
     100           0 :          a=a*factor
     101             : 
     102             :          ! now, the real part of f(0) has to be moved to a(n1,n2,0) to get a purely
     103             :          ! complex array starting at a(1,1,0)
     104             : 
     105           0 :          DO i1=1,n1
     106           0 :             DO i2=1,n2
     107           0 :                a(i1,i2,0)=a(i1,i2,1)
     108           0 :                a(i1,i2,1)=0.0
     109             :             ENDDO
     110             :          ENDDO
     111             : 
     112             :       ENDIF
     113             : 
     114             : ! ******************** g e n e r a l  p a r t *******************
     115             : 
     116             : ! now perform n2*n3/2 and n1*n3/2 complex FFT's; a is assumed to be
     117             : ! complex and starting at (1,1,0)
     118             : 
     119           0 :       IF (ABS((n3/2.)-NINT(n3/2.)) > 0.1) THEN
     120             :          nup = n3
     121             :       ELSE
     122           0 :          nup = n3+1
     123           0 :          IF (n3+1>n3d)  CALL juDFT_error("n3 even & n3+1 > n3d" ,calledby &
     124           0 :                                          ="rfft")
     125           0 :          a(:,:,n3+1)=0.0
     126             :       ENDIF
     127             : 
     128           0 :       IF (l_nopad) THEN
     129           0 :          DO i3=1,nup,2
     130           0 :             CALL cfft(a(1,1,i3-1),a(1,1,i3),n1*n2,n1,n1,isn)
     131           0 :             CALL cfft(a(1,1,i3-1),a(1,1,i3),n1*n2,n2,n1*n2,isn)
     132             :          ENDDO
     133             :       ELSE
     134           0 :          DO i3=1,nup,2
     135           0 :             CALL cfft(a(1,1,i3-1),a(1,1,i3),(nw2+1)*n1,n1,n1,isn)
     136             :             CALL cfft(a(1,n2-nw2+1,i3-1),a(1,n2-nw2+1,i3), &
     137           0 :                       nw2*n1,n1,n1,isn)
     138           0 :             CALL cfft(a(1,1,i3-1),a(1,1,i3),n1*n2,n2,n1*n2,isn)
     139             :          ENDDO
     140             :       ENDIF
     141             : 
     142             : ! ******************** b a c k w a r d - t r a n s f o r m *******************
     143             : 
     144           0 :       IF (isn == -1) THEN
     145             : 
     146             :          ! the real part of f(0) has to be moved to a(n1,n2,1) for a correct
     147             :          ! setup for vrfftb (see comments therein)
     148             : 
     149           0 :          DO i1=1,n1
     150           0 :             DO i2=1,n2
     151           0 :                a(i1,i2,1)=a(i1,i2,0)
     152           0 :                a(i1,i2,0)=0.0
     153             :             ENDDO
     154             :          ENDDO
     155             : 
     156             :          ! transform n1*n2 mixed real and complex sequences of lenghth n3/2
     157             :          ! to n3 real values
     158             : 
     159           0 :          CALL vrffti(n3,wsave)
     160           0 :          IF (l_nopad) THEN
     161           0 :             CALL vrfftb(n1*n2,n3,a(1,1,1),b,n1d*n2d,wsave)
     162             :          ELSE
     163           0 :             DO i2=1,nw2+1
     164           0 :                CALL vrfftb(nw1+1,n3,a(1,i2,1),b,n1d*n2d,wsave)
     165           0 :                CALL vrfftb(nw1  ,n3,a(n1-nw1+1,i2,1),b,n1d*n2d,wsave)
     166             :             ENDDO
     167           0 :             DO i2=n2-nw2+1,n2
     168           0 :                CALL vrfftb(nw1+1,n3,a(1,i2,1),b,n1d*n2d,wsave)
     169           0 :                CALL vrfftb(nw1  ,n3,a(n1-nw1+1,i2,1),b,n1d*n2d,wsave)
     170             :             ENDDO
     171             :          ENDIF
     172             : 
     173             :          ! remove the norm 1/sqrt(n3) (compatibility with cfft)
     174             : 
     175           0 :          factor = sqrt(1.0*n3)
     176             :          ! ALL CPP_BLAS_sscal(n1d*n2d*n3,factor,a(1,1,1),1)
     177           0 :          a=a*factor
     178             : 
     179             :       ENDIF
     180             : 
     181           0 :    END SUBROUTINE rfft
     182             : 
     183           0 :    SUBROUTINE vrffti(n,wsave)
     184             : !***BEGIN PROLOGUE  VRFFTI
     185             : !***DATE WRITTEN   860701   (YYMMDD)
     186             : !***REVISION DATE  900509   (YYMMDD)
     187             : !***CATEGORY NO.  J1A1
     188             : !***KEYWORDS  FAST FOURIER TRANSFORM, REAL PERIODIC TRANSFORM,
     189             : !             MULTIPLE SEQUENCES
     190             : !***AUTHOR  SWEET, R.A. (NIST) AND LINDGREN, L.L. (NIST)
     191             : !***PURPOSE  Initialization for VRFFTF and VRFFTB.
     192             : !***DESCRIPTION
     193             : 
     194             : !  Subroutine VRFFTI initializes the array WSAVE which is used in
     195             : !  both VRFFTF and VRFFTB.  The prime factorization of N together with
     196             : !  a tabulation of certain trigonometric functions are computed and
     197             : !  stored in the array WSAVE.
     198             : 
     199             : !  Input Parameter
     200             : 
     201             : !  N       the length of the sequence to be transformed.  There is no
     202             : !          restriction on N.
     203             : 
     204             : !  Output Parameter
     205             : 
     206             : !  WSAVE   a work array which must be dimensioned at least N+15.
     207             : !          The same work array can be used for both VRFFTF and VRFFTB
     208             : !          as long as N remains unchanged.  Different WSAVE arrays
     209             : !          are required for different values of N.  The contents of
     210             : !          WSAVE must not be changed between calls of VRFFTF or VRFFTB.
     211             : 
     212             : !              * * * * * * * * * * * * * * * * * * * * *
     213             : !              *                                       *
     214             : !              *         PROGRAM SPECIFICATIONS        *
     215             : !              *                                       *
     216             : !              * * * * * * * * * * * * * * * * * * * * *
     217             : 
     218             : !     Dimension of    R(MDIMR,N), RT(MDIMR,N), WSAVE(N+15)
     219             : !     Arguments
     220             : 
     221             : !     Latest          AUGUST 1, 1985
     222             : !     Revision
     223             : 
     224             : !     Subprograms     VRFFTI, VRFTI1, VRFFTF, VRFTF1, VRADF2, VRADF3,
     225             : !     Required        VRADF4, VRADF5, VRADFG, VRFFTB, VRFTB1, VRADB2,
     226             : !                     VRADB3, VRADB4, VRADB5, VRADBG, PIMACH
     227             : 
     228             : !     Special         NONE
     229             : !     Conditions
     230             : 
     231             : !     Common          NONE
     232             : !     blocks
     233             : 
     234             : !     I/O             NONE
     235             : 
     236             : !     Precision       SINGLE
     237             : 
     238             : !     Specialist      ROLAND SWEET
     239             : 
     240             : !     Language        FORTRAN
     241             : 
     242             : !     History         WRITTEN BY LINDA LINDGREN AND ROLAND SWEET AT THE
     243             : !                     NATIONAL BUREAU OF STANDARDS (BOULDER).
     244             : 
     245             : !     Algorithm       A REAL VARIANT OF THE STOCKHAM AUTOSORT VERSION
     246             : !                     OF THE COOLEY-TUKEY FAST FOURIER TRANSFORM.
     247             : 
     248             : !     Portability     AMERICAN NATIONAL STANDARDS INSTITUTE FORTRAN 77.
     249             : !                     THE ONLY MACHINE DEPENDENT CONSTANT IS LOCATED IN
     250             : !                     THE FUNCTION PIMACH.
     251             : 
     252             : !     Required        COS,SIN
     253             : !     resident
     254             : !     Routines
     255             : 
     256             : !***REFERENCES  P. N. Swarztrauber, Vectorizing the FFTs, in Parallel
     257             : !               Computations, (G. Rodrigue, ed.), Academic Press, 1982,
     258             : !               pp. 51-83.
     259             : !***ROUTINES CALLED  VRFTI1
     260             : !***END PROLOGUE  VRFFTI
     261             : 
     262             : !     VRFFTPK, VERSION 1, AUGUST 1985
     263             : 
     264             :       DIMENSION wsave(n+15)
     265             : !***FIRST EXECUTABLE STATEMENT  VRFFTI
     266           0 :       IF (n == 1) RETURN
     267           0 :       CALL vrfti1(n,wsave(1),wsave(n+1))
     268           0 :       RETURN
     269             :    END subroutine
     270           0 :    SUBROUTINE vrfti1(n,wa,fac)
     271             : 
     272             : !     VRFFTPK, VERSION 1, AUGUST 1985
     273             : 
     274             :       USE m_constants, ONLY : pimach
     275             :       DIMENSION wa(n),fac(15),ntryh(4)
     276             :       DATA ntryh(1),ntryh(2),ntryh(3),ntryh(4)/4,2,3,5/
     277             : 
     278           0 :       nl = n
     279           0 :       nf = 0
     280           0 :       j = 0
     281           0 : 10    j = j + 1
     282           0 :       IF ( j <=4 ) THEN
     283           0 :          ntry = ntryh(j)
     284             :       ELSE
     285           0 :          ntry = ntry + 2
     286             :       ENDIF
     287           0 : 40    nq = nl/ntry
     288           0 :       nr = nl - ntry*nq
     289           0 :       IF ( nr /= 0 ) THEN
     290             :          GOTO 10
     291             :       ENDIF
     292           0 :       nf = nf + 1
     293           0 :       fac(nf+2) = ntry
     294           0 :       nl = nq
     295           0 :       IF (ntry /= 2) GO TO 70
     296           0 :       IF (nf == 1) GO TO 70
     297           0 :       DO 60 i = 2,nf
     298           0 :          ib = nf - i + 2
     299           0 :          fac(ib+2) = fac(ib+1)
     300           0 : 60    END DO
     301           0 :       fac(3) = 2
     302           0 : 70    IF (nl /= 1) GO TO 40
     303           0 :       fac(1) = n
     304           0 :       fac(2) = nf
     305           0 :       tpi = 2.*pimach()
     306           0 :       argh = tpi/real(n)
     307           0 :       is = 0
     308           0 :       nfm1 = nf - 1
     309           0 :       l1 = 1
     310           0 :       IF (nfm1 == 0) RETURN
     311           0 :       DO 100 k1 = 1,nfm1
     312           0 :          ip = fac(k1+2)
     313           0 :          ld = 0
     314           0 :          l2 = l1*ip
     315           0 :          ido = n/l2
     316           0 :          ipm = ip - 1
     317           0 :          DO 90 j = 1,ipm
     318           0 :             ld = ld + l1
     319           0 :             i = is
     320           0 :             argld = real(ld)*argh
     321           0 :             fi = 0.
     322           0 :             DO 80 ii = 3,ido,2
     323           0 :                i = i + 2
     324           0 :                fi = fi + 1.
     325           0 :                arg = fi*argld
     326           0 :                wa(i-1) = cos(arg)
     327           0 :                wa(i) = sin(arg)
     328           0 : 80          END DO
     329           0 :             is = is + ido
     330           0 : 90       END DO
     331           0 :          l1 = l2
     332           0 : 100   END DO
     333             :       RETURN
     334             :    END subroutine
     335           0 :    SUBROUTINE vrfftf(m,n,r,rt,mdimr,wsave)
     336             : 
     337             : !***BEGIN PROLOGUE  VRFFTF
     338             : !***DATE WRITTEN   850801   (YYMMDD)
     339             : !***REVISION DATE  900509   (YYMMDD)
     340             : !***CATEGORY NO.  J1A1
     341             : !***KEYWORDS  FAST FOURIER TRANSFORM, REAL PERIODIC TRANSFORM,
     342             : !             FOURIER ANALYSIS, FORWARD TRANSFORM, MULTIPLE SEQUENCES
     343             : !***AUTHOR  SWEET, R.A. (NIST) AND LINDGREN, L.L. (NIST)
     344             : !***PURPOSE  Forward real periodic transform, M sequences.
     345             : !***DESCRIPTION
     346             : 
     347             : !  Subroutine VRFFTF computes the Fourier coefficients (forward
     348             : !  transform) of a number of real periodic sequences.  Specifically,
     349             : !  for each sequence the subroutine claculates the independent
     350             : !  Fourier coefficients described below at output parameter R.
     351             : 
     352             : !  The array WSAVE which is used by subroutine VRFFTF must be
     353             : !  initialized by calling subroutine VRFFTI(N,WSAVE).
     354             : 
     355             : !  Input Parameters
     356             : 
     357             : !  M       the number of sequences to be transformed.
     358             : 
     359             : !  N       the length of the sequences to be transformed.  The method
     360             : !          is most efficient when N is a product of small primes,
     361             : !          however n may be any positive integer.
     362             : 
     363             : !  R       areal two-dimensional array of size MDIMX x N containing the
     364             : !          the sequences to be transformed.  The sequences are stored
     365             : !          in the ROWS of R.  Thus, the I-th sequence to be transformed,
     366             : !          X(I,J), J=0,1,...,N-1, is stored as
     367             : 
     368             : !               R(I,J) = X(I,J-1) , J=1, 2, . . . , N.
     369             : 
     370             : !  RT      a real two-dimensional work array of size MDIMX x N.
     371             : 
     372             : !  MDIMR   the row (or first) dimension of the arrays R and RT exactly
     373             : !          as they appear in the calling program.  This parameter is
     374             : !          used to specify the variable dimension of these arrays.
     375             : 
     376             : !  WSAVE   a real one-dimensional work array which must be dimensioned
     377             : !          at least N+15.  The WSAVE array must be initialized by
     378             : !          calling subroutine VRFFTI.  A different WSAVE array must be
     379             : !          used for each different value of N.  This initialization does
     380             : !          not have to be repeated so long as N remains unchanged.  The
     381             : !          same WSAVE array may be used by VRFFTF and VRFFTB.
     382             : 
     383             : !  Output Parameters
     384             : 
     385             : !  R       contains the Fourier coefficients F(K) for each of the M
     386             : !          input sequences.  Specifically, row I of R, R(I,J),
     387             : !          J=1,2,..,N, contains the independent Fourier coefficients
     388             : !          F(I,K), for the I-th input sequence stored as
     389             : 
     390             : !             R(I,1) = REAL( F(I,0) ),
     391             : !                    = SQRT(1/N)*SUM(J=0,N-1)[ X(I,J) ],
     392             : 
     393             : !             R(I,2*K) = REAL( F(I,K) )
     394             : !                      = SQRT(1/N)*SUM(J=0,N-1)[X(I,J)*COS(2J*K*PI/N)]
     395             : 
     396             : !             R(I,2*K+1) = IMAG( F(I,K) )
     397             : !                        =-SQRT(1/N)*SUM(J=0,N-1)[X(I,J)*SIN(2J*K*PI/N)]
     398             : 
     399             : !                   for K = 1, 2, . . . , M-1,
     400             : 
     401             : !              and, when N is even,
     402             : 
     403             : !              R(I,N) = REAL( F(I,N/2) ).
     404             : !                     = SQRT(1/N)*SUM(J=0,N-1)[ (-1)**J*X(I,J) ].
     405             : 
     406             : !  WSAVE   contains results which must not be destroyed between calls
     407             : !          to VRFFTF or VRFFTB.
     408             : 
     409             : !  -----------------------------------------------------------------
     410             : 
     411             : !  NOTE  -  A call of VRFFTF followed immediately by a call of
     412             : !           of VRFFTB will return the original sequences R.  Thus,
     413             : !           VRFFTB is the correctly normalized inverse of VRFFTF.
     414             : 
     415             : !  -----------------------------------------------------------------
     416             : 
     417             : !  VRFFTF is a straightforward extension of the subprogram RFFTF to
     418             : !  handle M simultaneous sequences.  RFFTF was originally developed
     419             : !  by P. N. Swarztrauber of NCAR.
     420             : 
     421             : !              * * * * * * * * * * * * * * * * * * * * *
     422             : !              *                                       *
     423             : !              *         PROGRAM SPECIFICATIONS        *
     424             : !              *                                       *
     425             : !              * * * * * * * * * * * * * * * * * * * * *
     426             : 
     427             : !     Dimension of    R(MDIMR,N), RT(MDIMR,N), WSAVE(N+15)
     428             : !     Arguments
     429             : 
     430             : !     Latest          AUGUST 1, 1985
     431             : !     Revision
     432             : 
     433             : !     Subprograms     VRFFTI, VRFTI1, VRFFTF, VRFTF1, VRADF2, VRADF3,
     434             : !     Required        VRADF4, VRADF5, VRADFG, VRFFTB, VRFTB1, VRADB2,
     435             : !                     VRADB3, VRADB4, VRADB5, VRADBG, PIMACH
     436             : 
     437             : !     Special         NONE
     438             : !     Conditions
     439             : 
     440             : !     Common          NONE
     441             : !     blocks
     442             : 
     443             : !     I/O             NONE
     444             : 
     445             : !     Precision       SINGLE
     446             : 
     447             : !     Specialist      ROLAND SWEET
     448             : 
     449             : !     Language        FORTRAN
     450             : 
     451             : !     History         WRITTEN BY LINDA LINDGREN AND ROLAND SWEET AT THE
     452             : !                     NATIONAL BUREAU OF STANDARDS (BOULDER).
     453             : 
     454             : !     Algorithm       A REAL VARIANT OF THE STOCKHAM AUTOSORT VERSION
     455             : !                     OF THE COOLEY-TUKEY FAST FOURIER TRANSFORM.
     456             : 
     457             : !     Portability     AMERICAN NATIONAL STANDARDS INSTITUTE FORTRAN 77.
     458             : !                     THE ONLY MACHINE DEPENDENT CONSTANT IS LOCATED IN
     459             : !                     THE FUNCTION PIMACH.
     460             : 
     461             : !     Required        COS,SIN
     462             : !     resident
     463             : !     Routines
     464             : 
     465             : !***REFERENCES  P. N. Swarztrauber, Vectorizing the FFTs, in Parallel
     466             : !               Computations, (G. Rodrigue, ed.), Academic Press, 1982,
     467             : !               pp. 51-83.
     468             : !***ROUTINES CALLED  VRFTF1
     469             : !***END PROLOGUE  VRFFTF
     470             : 
     471             : !     VRFFTPK, VERSION 1, AUGUST 1985
     472             : 
     473             :       DIMENSION r(mdimr,n),rt(mdimr,n),wsave(n+15)
     474             : !***FIRST EXECUTABLE STATEMENT  VRFFTF
     475           0 :       IF (n == 1) RETURN
     476           0 :       CALL vrftf1(m,n,r,rt,mdimr,wsave(1),wsave(n+1))
     477           0 :       RETURN
     478             :    END subroutine
     479           0 :    SUBROUTINE vradf2(mp,ido,l1,cc,ch,mdimc,wa1)
     480             : 
     481             : !     VRFFTPK, VERSION 1, AUGUST 1985
     482             : 
     483             :       DIMENSION ch(mdimc,ido,2,l1),cc(mdimc,ido,l1,2),wa1(ido)
     484             : 
     485           0 :       DO 20 k = 1,l1
     486           0 :          DO 10 m = 1,mp
     487           0 :             ch(m,1,1,k) = cc(m,1,k,1) + cc(m,1,k,2)
     488           0 :             ch(m,ido,2,k) = cc(m,1,k,1) - cc(m,1,k,2)
     489           0 : 10       END DO
     490           0 : 20    END DO
     491           0 :       IF ( ido ==  2 ) THEN
     492             :          GOTO 70
     493           0 :       ELSEIF ( ido < 2 ) THEN
     494             :          GOTO 100
     495             :       ENDIF
     496           0 :       idp2 = ido + 2
     497           0 :       DO 60 k = 1,l1
     498           0 :          DO 50 i = 3,ido,2
     499           0 :             ic = idp2 - i
     500           0 :             DO 40 m = 1,mp
     501             :                ch(m,i,1,k) = cc(m,i,k,1) + &
     502             :                              (wa1(i-2)*cc(m,i,k,2)-wa1(i-1)* &
     503           0 :                               cc(m,i-1,k,2))
     504             :                ch(m,ic,2,k) = (wa1(i-2)*cc(m,i,k,2)- &
     505           0 :                                wa1(i-1)*cc(m,i-1,k,2)) - cc(m,i,k,1)
     506             :                ch(m,i-1,1,k) = cc(m,i-1,k,1) + &
     507             :                                (wa1(i-2)*cc(m,i-1,k,2)+wa1(i-1)* &
     508           0 :                                 cc(m,i,k,2))
     509             :                ch(m,ic-1,2,k) = cc(m,i-1,k,1) - &
     510             :                                 (wa1(i-2)*cc(m,i-1,k,2)+wa1(i-1)* &
     511           0 :                                  cc(m,i,k,2))
     512           0 : 40          END DO
     513           0 : 50       END DO
     514           0 : 60    END DO
     515           0 :       IF (mod(ido,2) == 1) RETURN
     516           0 : 70    DO 90 k = 1,l1
     517           0 :          DO 80 m = 1,mp
     518           0 :             ch(m,1,2,k) = -cc(m,ido,k,2)
     519           0 :             ch(m,ido,1,k) = cc(m,ido,k,1)
     520           0 : 80       END DO
     521           0 : 90    END DO
     522             : 100   RETURN
     523             :    END subroutine
     524           0 :    SUBROUTINE vradf3(mp,ido,l1,cc,ch,mdimc,wa1,wa2)
     525             : 
     526             : !     VRFFTPK, VERSION 1, AUGUST 1985
     527             : 
     528             :       USE m_constants, ONLY : pimach
     529             :       DIMENSION ch(mdimc,ido,3,l1),cc(mdimc,ido,l1,3),wa1(ido),wa2(ido)
     530             : 
     531           0 :       arg = 2.*pimach()/3.
     532           0 :       taur = cos(arg)
     533           0 :       taui = sin(arg)
     534           0 :       DO 20 k = 1,l1
     535           0 :          DO 10 m = 1,mp
     536           0 :             ch(m,1,1,k) = cc(m,1,k,1) + (cc(m,1,k,2)+cc(m,1,k,3))
     537           0 :             ch(m,1,3,k) = taui* (cc(m,1,k,3)-cc(m,1,k,2))
     538             :             ch(m,ido,2,k) = cc(m,1,k,1) + &
     539           0 :                             taur* (cc(m,1,k,2)+cc(m,1,k,3))
     540           0 : 10       END DO
     541           0 : 20    END DO
     542           0 :       IF (ido == 1) RETURN
     543           0 :       idp2 = ido + 2
     544           0 :       DO 50 k = 1,l1
     545           0 :          DO 40 i = 3,ido,2
     546           0 :             ic = idp2 - i
     547           0 :             DO 30 m = 1,mp
     548             :                ch(m,i-1,1,k) = cc(m,i-1,k,1) + &
     549             :                ((wa1(i-2)*cc(m,i-1,k,2)+wa1(i-1)*cc(m,i, &
     550             :                k,2))+ (wa2(i-2)*cc(m,i-1,k, &
     551           0 :                &                          3)+wa2(i-1)*cc(m,i,k,3)))
     552             :                ch(m,i,1,k) = cc(m,i,k,1) + &
     553             :                ((wa1(i-2)*cc(m,i,k,2)-wa1(i-1)*cc(m,i-1,k, &
     554             :                &                        2))+ (wa2(i-2)*cc(m,i,k,3)-wa2(i-1)*cc(m, &
     555           0 :                i-1,k,3)))
     556             :                ch(m,i-1,3,k) = (cc(m,i-1,k,1)+ &
     557             :                taur* ((wa1(i-2)*cc(m,i-1,k, &
     558             :                &                          2)+wa1(i-1)*cc(m,i,k,2))+ (wa2(i-2)*cc(m, &
     559             :                i-1,k,3)+wa2(i-1)*cc(m,i,k,3)))) + &
     560             :                (taui* ((wa1(i-2)*cc(m,i,k, &
     561             :                &                          2)-wa1(i-1)*cc(m,i-1,k, &
     562             :                &                          2))- (wa2(i-2)*cc(m,i,k,3)-wa2(i-1)*cc(m, &
     563           0 :                i-1,k,3))))
     564             :                ch(m,ic-1,2,k) = (cc(m,i-1,k,1)+ &
     565             :                taur* ((wa1(i-2)*cc(m,i-1,k, &
     566             :                &                           2)+wa1(i-1)*cc(m,i,k, &
     567             :                &                           2))+ (wa2(i-2)*cc(m,i-1,k, &
     568             :                &                           3)+wa2(i-1)*cc(m,i,k,3)))) - &
     569             :                (taui* ((wa1(i-2)*cc(m,i,k, &
     570             :                &                           2)-wa1(i-1)*cc(m,i-1,k, &
     571             :                &                           2))- (wa2(i-2)*cc(m,i,k, &
     572           0 :                &                           3)-wa2(i-1)*cc(m,i-1,k,3))))
     573             :                ch(m,i,3,k) = (cc(m,i,k,1)+taur* &
     574             :                ((wa1(i-2)*cc(m,i,k,2)-wa1(i-1)*cc(m,i-1,k, &
     575             :                &                        2))+ (wa2(i-2)*cc(m,i,k,3)-wa2(i-1)*cc(m, &
     576             :                i-1,k,3)))) + (taui* ((wa2(i-2)*cc(m,i-1,k, &
     577             :                &                        3)+wa2(i-1)*cc(m,i,k,3))- (wa1(i-2)*cc(m, &
     578           0 :                i-1,k,2)+wa1(i-1)*cc(m,i,k,2))))
     579             :                ch(m,ic,2,k) = (taui* ((wa2(i-2)*cc(m,i-1,k, &
     580             :                &                         3)+wa2(i-1)*cc(m,i,k,3))- (wa1(i-2)*cc(m, &
     581             :                i-1,k,2)+wa1(i-1)*cc(m,i,k,2)))) - &
     582             :                (cc(m,i,k,1)+taur* ((wa1(i-2)*cc(m,i,k, &
     583             :                &                         2)-wa1(i-1)*cc(m,i-1,k, &
     584             :                &                         2))+ (wa2(i-2)*cc(m,i,k,3)-wa2(i-1)*cc(m, &
     585           0 :                i-1,k,3))))
     586           0 : 30          END DO
     587           0 : 40       END DO
     588           0 : 50    END DO
     589             :       RETURN
     590             :    END subroutine
     591           0 :    SUBROUTINE vradf4(mp,ido,l1,cc,ch,mdimc,wa1,wa2,wa3)
     592             : 
     593             : !     VRFFTPK, VERSION 1, AUGUST 1985
     594             : 
     595             :       DIMENSION cc(mdimc,ido,l1,4),ch(mdimc,ido,4,l1),wa1(ido),wa2(ido), &
     596             :          wa3(ido)
     597             : 
     598           0 :       hsqt2 = sqrt(2.)/2.
     599           0 :       DO 20 k = 1,l1
     600           0 :          DO 10 m = 1,mp
     601             :             ch(m,1,1,k) = (cc(m,1,k,2)+cc(m,1,k,4)) + &
     602           0 :                           (cc(m,1,k,1)+cc(m,1,k,3))
     603             :             ch(m,ido,4,k) = (cc(m,1,k,1)+cc(m,1,k,3)) - &
     604           0 :                             (cc(m,1,k,2)+cc(m,1,k,4))
     605           0 :             ch(m,ido,2,k) = cc(m,1,k,1) - cc(m,1,k,3)
     606           0 :             ch(m,1,3,k) = cc(m,1,k,4) - cc(m,1,k,2)
     607           0 : 10       END DO
     608           0 : 20    END DO
     609           0 :       IF ( ido ==  2 ) THEN
     610             :          GOTO 70
     611           0 :       ELSEIF ( ido < 2 ) THEN
     612             :          GOTO 100
     613             :       ENDIF
     614           0 :       idp2 = ido + 2
     615           0 :       DO 60 k = 1,l1
     616           0 :          DO 50 i = 3,ido,2
     617           0 :             ic = idp2 - i
     618           0 :             DO 40 m = 1,mp
     619             :                ch(m,i-1,1,k) = ((wa1(i-2)*cc(m,i-1,k,2)+wa1(i-1)*cc(m,i, &
     620             :                k,2))+ (wa3(i-2)*cc(m,i-1,k, &
     621             :                &                          4)+wa3(i-1)*cc(m,i,k,4))) + &
     622             :                (cc(m,i-1,k,1)+ (wa2(i-2)*cc(m,i-1,k, &
     623           0 :                &                          3)+wa2(i-1)*cc(m,i,k,3)))
     624             :                ch(m,ic-1,4,k) = (cc(m,i-1,k,1)+ &
     625             :                (wa2(i-2)*cc(m,i-1,k,3)+wa2(i-1)*cc(m,i, &
     626             :                k,3))) - ((wa1(i-2)*cc(m,i-1,k, &
     627             :                &                           2)+wa1(i-1)*cc(m,i,k,2))+ &
     628             :                (wa3(i-2)*cc(m,i-1,k,4)+wa3(i-1)*cc(m,i, &
     629           0 :                k,4)))
     630             :                ch(m,i,1,k) = ((wa1(i-2)*cc(m,i,k,2)-wa1(i-1)*cc(m,i-1,k, &
     631             :                &                        2))+ (wa3(i-2)*cc(m,i,k,4)-wa3(i-1)*cc(m, &
     632             :                i-1,k,4))) + (cc(m,i,k,1)+ &
     633             :                (wa2(i-2)*cc(m,i,k,3)-wa2(i-1)*cc(m,i-1,k, &
     634           0 :                &                        3)))
     635             :                ch(m,ic,4,k) = ((wa1(i-2)*cc(m,i,k,2)-wa1(i-1)*cc(m,i-1, &
     636             :                k,2))+ (wa3(i-2)*cc(m,i,k, &
     637             :                &                         4)-wa3(i-1)*cc(m,i-1,k,4))) - &
     638             :                (cc(m,i,k,1)+ (wa2(i-2)*cc(m,i,k, &
     639           0 :                &                         3)-wa2(i-1)*cc(m,i-1,k,3)))
     640             :                ch(m,i-1,3,k) = ((wa1(i-2)*cc(m,i,k,2)-wa1(i-1)*cc(m,i-1, &
     641             :                k,2))- (wa3(i-2)*cc(m,i,k, &
     642             :                &                          4)-wa3(i-1)*cc(m,i-1,k,4))) + &
     643             :                (cc(m,i-1,k,1)- (wa2(i-2)*cc(m,i-1,k, &
     644           0 :                &                          3)+wa2(i-1)*cc(m,i,k,3)))
     645             :                ch(m,ic-1,2,k) = (cc(m,i-1,k,1)- &
     646             :                (wa2(i-2)*cc(m,i-1,k,3)+wa2(i-1)*cc(m,i, &
     647             :                k,3))) - ((wa1(i-2)*cc(m,i,k, &
     648             :                &                           2)-wa1(i-1)*cc(m,i-1,k,2))- &
     649             :                (wa3(i-2)*cc(m,i,k,4)-wa3(i-1)*cc(m,i-1, &
     650           0 :                k,4)))
     651             :                ch(m,i,3,k) = ((wa3(i-2)*cc(m,i-1,k,4)+wa3(i-1)*cc(m,i,k, &
     652             :                &                        4))- (wa1(i-2)*cc(m,i-1,k,2)+wa1(i-1)*cc(m, &
     653             :                i,k,2))) + (cc(m,i,k,1)- &
     654             :                (wa2(i-2)*cc(m,i,k,3)-wa2(i-1)*cc(m,i-1,k, &
     655           0 :                &                        3)))
     656             :                ch(m,ic,2,k) = ((wa3(i-2)*cc(m,i-1,k,4)+wa3(i-1)*cc(m,i, &
     657             :                k,4))- (wa1(i-2)*cc(m,i-1,k, &
     658             :                &                         2)+wa1(i-1)*cc(m,i,k,2))) - &
     659             :                (cc(m,i,k,1)- (wa2(i-2)*cc(m,i,k, &
     660           0 :                &                         3)-wa2(i-1)*cc(m,i-1,k,3)))
     661           0 : 40          END DO
     662           0 : 50       END DO
     663           0 : 60    END DO
     664           0 :       IF (mod(ido,2) == 1) RETURN
     665             : 70    CONTINUE
     666           0 :       DO 90 k = 1,l1
     667           0 :          DO 80 m = 1,mp
     668             :             ch(m,ido,1,k) = (hsqt2* (cc(m,ido,k,2)-cc(m,ido,k,4))) + &
     669           0 :                             cc(m,ido,k,1)
     670             :             ch(m,ido,3,k) = cc(m,ido,k,1) - &
     671           0 :                             (hsqt2* (cc(m,ido,k,2)-cc(m,ido,k,4)))
     672             :             ch(m,1,2,k) = (-hsqt2* (cc(m,ido,k,2)+cc(m,ido,k,4))) - &
     673           0 :                           cc(m,ido,k,3)
     674             :             ch(m,1,4,k) = (-hsqt2* (cc(m,ido,k,2)+cc(m,ido,k,4))) + &
     675           0 :                           cc(m,ido,k,3)
     676           0 : 80       END DO
     677           0 : 90    END DO
     678             : 100   RETURN
     679             :    END subroutine
     680           0 :    SUBROUTINE vradf5(mp,ido,l1,cc,ch,mdimc,wa1,wa2,wa3,wa4)
     681             : 
     682             : !     VRFFTPK, VERSION 1, AUGUST 1985
     683             : 
     684             :       USE m_constants, ONLY : pimach
     685             :       DIMENSION cc(mdimc,ido,l1,5),ch(mdimc,ido,5,l1),wa1(ido),wa2(ido), &
     686             :          wa3(ido),wa4(ido)
     687             : 
     688           0 :       arg = 2.*pimach()/5.
     689           0 :       tr11 = cos(arg)
     690           0 :       ti11 = sin(arg)
     691           0 :       tr12 = cos(2.*arg)
     692           0 :       ti12 = sin(2.*arg)
     693           0 :       DO 20 k = 1,l1
     694           0 :          DO 10 m = 1,mp
     695             :             ch(m,1,1,k) = cc(m,1,k,1) + (cc(m,1,k,5)+cc(m,1,k,2)) + &
     696           0 :                           (cc(m,1,k,4)+cc(m,1,k,3))
     697             :             ch(m,ido,2,k) = cc(m,1,k,1) + &
     698             :                             tr11* (cc(m,1,k,5)+cc(m,1,k,2)) + &
     699           0 :                             tr12* (cc(m,1,k,4)+cc(m,1,k,3))
     700             :             ch(m,1,3,k) = ti11* (cc(m,1,k,5)-cc(m,1,k,2)) + &
     701           0 :                           ti12* (cc(m,1,k,4)-cc(m,1,k,3))
     702             :             ch(m,ido,4,k) = cc(m,1,k,1) + &
     703             :                             tr12* (cc(m,1,k,5)+cc(m,1,k,2)) + &
     704           0 :                             tr11* (cc(m,1,k,4)+cc(m,1,k,3))
     705             :             ch(m,1,5,k) = ti12* (cc(m,1,k,5)-cc(m,1,k,2)) - &
     706           0 :                           ti11* (cc(m,1,k,4)-cc(m,1,k,3))
     707           0 : 10       END DO
     708           0 : 20    END DO
     709           0 :       IF (ido == 1) RETURN
     710           0 :       idp2 = ido + 2
     711           0 :       DO 50 k = 1,l1
     712           0 :          DO 40 i = 3,ido,2
     713           0 :             ic = idp2 - i
     714           0 :             DO 30 m = 1,mp
     715             :                ch(m,i-1,1,k) = cc(m,i-1,k,1) + &
     716             :                ((wa1(i-2)*cc(m,i-1,k,2)+wa1(i-1)*cc(m,i, &
     717             :                k,2))+ (wa4(i-2)*cc(m,i-1,k, &
     718             :                &                          5)+wa4(i-1)*cc(m,i,k,5))) + &
     719             :                ((wa2(i-2)*cc(m,i-1,k,3)+wa2(i-1)*cc(m,i, &
     720             :                k,3))+ (wa3(i-2)*cc(m,i-1,k, &
     721           0 :                &                          4)+wa3(i-1)*cc(m,i,k,4)))
     722             :                ch(m,i,1,k) = cc(m,i,k,1) + &
     723             :                ((wa1(i-2)*cc(m,i,k,2)-wa1(i-1)*cc(m,i-1,k, &
     724             :                &                        2))+ (wa4(i-2)*cc(m,i,k,5)-wa4(i-1)*cc(m, &
     725             :                i-1,k,5))) + ((wa2(i-2)*cc(m,i,k, &
     726             :                &                        3)-wa2(i-1)*cc(m,i-1,k,3))+ &
     727             :                (wa3(i-2)*cc(m,i,k,4)-wa3(i-1)*cc(m,i-1,k, &
     728           0 :                &                        4)))
     729             :                ch(m,i-1,3,k) = cc(m,i-1,k,1) + &
     730             :                                tr11* (wa1(i-2)*cc(m,i-1,k,2)+ &
     731             :                                       wa1(i-1)*cc(m,i,k,2)+ &
     732             :                                       wa4(i-2)*cc(m,i-1,k,5)+ &
     733             :                                       wa4(i-1)*cc(m,i,k,5)) + &
     734             :                                tr12* (wa2(i-2)*cc(m,i-1,k,3)+ &
     735             :                                       wa2(i-1)*cc(m,i,k,3)+ &
     736             :                                       wa3(i-2)*cc(m,i-1,k,4)+ &
     737             :                                       wa3(i-1)*cc(m,i,k,4)) + &
     738             :                                ti11* (wa1(i-2)*cc(m,i,k,2)- &
     739             :                                       wa1(i-1)*cc(m,i-1,k,2)- &
     740             :                                       (wa4(i-2)*cc(m,i,k,5)-wa4(i-1)*cc(m,i-1, &
     741             :                                                                         k,5))) + ti12* (wa2(i-2)*cc(m,i,k,3)- &
     742             :                                                                                         wa2(i-1)*cc(m,i-1,k,3)- &
     743             :                                                                                         (wa3(i-2)*cc(m,i,k,4)-wa3(i-1)*cc(m,i-1, &
     744           0 :                                                                                                                           k,4)))
     745             :                ch(m,ic-1,2,k) = cc(m,i-1,k,1) + &
     746             :                tr11* (wa1(i-2)*cc(m,i-1,k,2)+ &
     747             :                wa1(i-1)*cc(m,i,k,2)+ &
     748             :                wa4(i-2)*cc(m,i-1,k,5)+ &
     749             :                wa4(i-1)*cc(m,i,k,5)) + &
     750             :                tr12* (wa2(i-2)*cc(m,i-1,k,3)+ &
     751             :                wa2(i-1)*cc(m,i,k,3)+ &
     752             :                wa3(i-2)*cc(m,i-1,k,4)+ &
     753             :                wa3(i-1)*cc(m,i,k,4)) - &
     754             :                (ti11* (wa1(i-2)*cc(m,i,k, &
     755             :                &                           2)-wa1(i-1)*cc(m,i-1,k, &
     756             :                &                           2)- (wa4(i-2)*cc(m,i,k,5)-wa4(i-1)*cc(m, &
     757             :                i-1,k,5)))+ti12* (wa2(i-2)*cc(m,i,k, &
     758             :                &                           3)-wa2(i-1)*cc(m,i-1,k, &
     759             :                &                           3)- (wa3(i-2)*cc(m,i,k,4)-wa3(i-1)*cc(m, &
     760           0 :                i-1,k,4))))
     761             :                ch(m,i,3,k) = (cc(m,i,k,1)+tr11* &
     762             :                ((wa1(i-2)*cc(m,i,k,2)-wa1(i-1)*cc(m,i-1,k, &
     763             :                &                        2))+ (wa4(i-2)*cc(m,i,k,5)-wa4(i-1)*cc(m, &
     764             :                i-1,k,5)))+tr12* ((wa2(i-2)*cc(m,i,k, &
     765             :                &                        3)-wa2(i-1)*cc(m,i-1,k,3))+ (wa3(i-2)*cc(m, &
     766             :                i,k,4)-wa3(i-1)*cc(m,i-1,k,4)))) + &
     767             :                (ti11* ((wa4(i-2)*cc(m,i-1,k, &
     768             :                &                        5)+wa4(i-1)*cc(m,i,k,5))- (wa1(i-2)*cc(m, &
     769             :                i-1,k,2)+wa1(i-1)*cc(m,i,k,2)))+ &
     770             :                ti12* ((wa3(i-2)*cc(m,i-1,k, &
     771             :                &                        4)+wa3(i-1)*cc(m,i,k,4))- (wa2(i-2)*cc(m, &
     772           0 :                i-1,k,3)+wa2(i-1)*cc(m,i,k,3))))
     773             :                ch(m,ic,2,k) = (ti11* ((wa4(i-2)*cc(m,i-1,k, &
     774             :                &                         5)+wa4(i-1)*cc(m,i,k,5))- (wa1(i-2)*cc(m, &
     775             :                i-1,k,2)+wa1(i-1)*cc(m,i,k,2)))+ &
     776             :                ti12* ((wa3(i-2)*cc(m,i-1,k, &
     777             :                &                         4)+wa3(i-1)*cc(m,i,k,4))- (wa2(i-2)*cc(m, &
     778             :                i-1,k,3)+wa2(i-1)*cc(m,i,k,3)))) - &
     779             :                (cc(m,i,k,1)+tr11* ((wa1(i-2)*cc(m,i,k, &
     780             :                &                         2)-wa1(i-1)*cc(m,i-1,k, &
     781             :                &                         2))+ (wa4(i-2)*cc(m,i,k,5)-wa4(i-1)*cc(m, &
     782             :                i-1,k,5)))+tr12* ((wa2(i-2)*cc(m,i,k, &
     783             :                &                         3)-wa2(i-1)*cc(m,i-1,k, &
     784             :                &                         3))+ (wa3(i-2)*cc(m,i,k,4)-wa3(i-1)*cc(m, &
     785           0 :                i-1,k,4))))
     786             :                ch(m,i-1,5,k) = (cc(m,i-1,k,1)+ &
     787             :                tr12* ((wa1(i-2)*cc(m,i-1,k, &
     788             :                &                          2)+wa1(i-1)*cc(m,i,k,2))+ (wa4(i-2)*cc(m, &
     789             :                i-1,k,5)+wa4(i-1)*cc(m,i,k,5)))+ &
     790             :                tr11* ((wa2(i-2)*cc(m,i-1,k, &
     791             :                &                          3)+wa2(i-1)*cc(m,i,k,3))+ (wa3(i-2)*cc(m, &
     792             :                i-1,k,4)+wa3(i-1)*cc(m,i,k,4)))) + &
     793             :                (ti12* ((wa1(i-2)*cc(m,i,k, &
     794             :                &                          2)-wa1(i-1)*cc(m,i-1,k, &
     795             :                &                          2))- (wa4(i-2)*cc(m,i,k,5)-wa4(i-1)*cc(m, &
     796             :                i-1,k,5)))-ti11* ((wa2(i-2)*cc(m,i,k, &
     797             :                &                          3)-wa2(i-1)*cc(m,i-1,k, &
     798             :                &                          3))- (wa3(i-2)*cc(m,i,k,4)-wa3(i-1)*cc(m, &
     799           0 :                i-1,k,4))))
     800             :                ch(m,ic-1,4,k) = (cc(m,i-1,k,1)+ &
     801             :                tr12* ((wa1(i-2)*cc(m,i-1,k, &
     802             :                &                           2)+wa1(i-1)*cc(m,i,k, &
     803             :                &                           2))+ (wa4(i-2)*cc(m,i-1,k, &
     804             :                &                           5)+wa4(i-1)*cc(m,i,k,5)))+ &
     805             :                tr11* ((wa2(i-2)*cc(m,i-1,k, &
     806             :                &                           3)+wa2(i-1)*cc(m,i,k, &
     807             :                &                           3))+ (wa3(i-2)*cc(m,i-1,k, &
     808             :                &                           4)+wa3(i-1)*cc(m,i,k,4)))) - &
     809             :                (ti12* ((wa1(i-2)*cc(m,i,k, &
     810             :                &                           2)-wa1(i-1)*cc(m,i-1,k, &
     811             :                &                           2))- (wa4(i-2)*cc(m,i,k, &
     812             :                &                           5)-wa4(i-1)*cc(m,i-1,k,5)))- &
     813             :                ti11* ((wa2(i-2)*cc(m,i,k, &
     814             :                &                           3)-wa2(i-1)*cc(m,i-1,k, &
     815             :                &                           3))- (wa3(i-2)*cc(m,i,k, &
     816           0 :                &                           4)-wa3(i-1)*cc(m,i-1,k,4))))
     817             :                ch(m,i,5,k) = (cc(m,i,k,1)+tr12* &
     818             :                ((wa1(i-2)*cc(m,i,k,2)-wa1(i-1)*cc(m,i-1,k, &
     819             :                &                        2))+ (wa4(i-2)*cc(m,i,k,5)-wa4(i-1)*cc(m, &
     820             :                i-1,k,5)))+tr11* ((wa2(i-2)*cc(m,i,k, &
     821             :                &                        3)-wa2(i-1)*cc(m,i-1,k,3))+ (wa3(i-2)*cc(m, &
     822             :                i,k,4)-wa3(i-1)*cc(m,i-1,k,4)))) + &
     823             :                (ti12* ((wa4(i-2)*cc(m,i-1,k, &
     824             :                &                        5)+wa4(i-1)*cc(m,i,k,5))- (wa1(i-2)*cc(m, &
     825             :                i-1,k,2)+wa1(i-1)*cc(m,i,k,2)))- &
     826             :                ti11* ((wa3(i-2)*cc(m,i-1,k, &
     827             :                &                        4)+wa3(i-1)*cc(m,i,k,4))- (wa2(i-2)*cc(m, &
     828           0 :                i-1,k,3)+wa2(i-1)*cc(m,i,k,3))))
     829             :                ch(m,ic,4,k) = (ti12* ((wa4(i-2)*cc(m,i-1,k, &
     830             :                &                         5)+wa4(i-1)*cc(m,i,k,5))- (wa1(i-2)*cc(m, &
     831             :                i-1,k,2)+wa1(i-1)*cc(m,i,k,2)))- &
     832             :                ti11* ((wa3(i-2)*cc(m,i-1,k, &
     833             :                &                         4)+wa3(i-1)*cc(m,i,k,4))- (wa2(i-2)*cc(m, &
     834             :                i-1,k,3)+wa2(i-1)*cc(m,i,k,3)))) - &
     835             :                (cc(m,i,k,1)+tr12* ((wa1(i-2)*cc(m,i,k, &
     836             :                &                         2)-wa1(i-1)*cc(m,i-1,k, &
     837             :                &                         2))+ (wa4(i-2)*cc(m,i,k,5)-wa4(i-1)*cc(m, &
     838             :                i-1,k,5)))+tr11* ((wa2(i-2)*cc(m,i,k, &
     839             :                &                         3)-wa2(i-1)*cc(m,i-1,k, &
     840             :                &                         3))+ (wa3(i-2)*cc(m,i,k,4)-wa3(i-1)*cc(m, &
     841           0 :                i-1,k,4))))
     842           0 : 30          END DO
     843           0 : 40       END DO
     844           0 : 50    END DO
     845             :       RETURN
     846             :    END subroutine
     847           0 :    SUBROUTINE vradfg(mp,ido,ip,l1,idl1,cc,c1,c2,ch,ch2,mdimc,wa)
     848             : 
     849             : !     VRFFTPK, VERSION 1, AUGUST 1985
     850             : 
     851             :       USE m_constants, ONLY : pimach
     852             :       DIMENSION ch(mdimc,ido,l1,ip),cc(mdimc,ido,ip,l1), &
     853             :          c1(mdimc,ido,l1,ip),c2(mdimc,idl1,ip), &
     854             :          ch2(mdimc,idl1,ip),wa(ido)
     855             : 
     856           0 :       tpi = 2.*pimach()
     857           0 :       arg = tpi/real(ip)
     858           0 :       dcp = cos(arg)
     859           0 :       dsp = sin(arg)
     860           0 :       ipph = (ip+1)/2
     861           0 :       ipp2 = ip + 2
     862           0 :       idp2 = ido + 2
     863           0 :       nbd = (ido-1)/2
     864           0 :       IF (ido == 1) GO TO 250
     865           0 :       DO 20 ik = 1,idl1
     866           0 :          DO 10 m = 1,mp
     867           0 :             ch2(m,ik,1) = c2(m,ik,1)
     868           0 : 10       END DO
     869           0 : 20    END DO
     870           0 :       DO 50 j = 2,ip
     871           0 :          DO 40 k = 1,l1
     872           0 :             DO 30 m = 1,mp
     873           0 :                ch(m,1,k,j) = c1(m,1,k,j)
     874           0 : 30          END DO
     875           0 : 40       END DO
     876           0 : 50    END DO
     877           0 :       IF (nbd > l1) GO TO 100
     878           0 :       is = -ido
     879           0 :       DO 90 j = 2,ip
     880           0 :          is = is + ido
     881           0 :          idij = is
     882           0 :          DO 80 i = 3,ido,2
     883           0 :             idij = idij + 2
     884           0 :             DO 70 k = 1,l1
     885           0 :                DO 60 m = 1,mp
     886             :                   ch(m,i-1,k,j) = wa(idij-1)*c1(m,i-1,k,j) + &
     887           0 :                                   wa(idij)*c1(m,i,k,j)
     888             :                   ch(m,i,k,j) = wa(idij-1)*c1(m,i,k,j) - &
     889           0 :                                 wa(idij)*c1(m,i-1,k,j)
     890           0 : 60             END DO
     891           0 : 70          END DO
     892           0 : 80       END DO
     893           0 : 90    END DO
     894           0 :       GO TO 150
     895           0 : 100   is = -ido
     896           0 :       DO 140 j = 2,ip
     897           0 :          is = is + ido
     898           0 :          DO 130 k = 1,l1
     899           0 :             idij = is
     900           0 :             DO 120 i = 3,ido,2
     901           0 :                idij = idij + 2
     902           0 :                DO 110 m = 1,mp
     903             :                   ch(m,i-1,k,j) = wa(idij-1)*c1(m,i-1,k,j) + &
     904           0 :                                   wa(idij)*c1(m,i,k,j)
     905             :                   ch(m,i,k,j) = wa(idij-1)*c1(m,i,k,j) - &
     906           0 :                                 wa(idij)*c1(m,i-1,k,j)
     907           0 : 110            END DO
     908           0 : 120         END DO
     909           0 : 130      END DO
     910           0 : 140   END DO
     911           0 : 150   IF (nbd < l1) GO TO 200
     912           0 :       DO 190 j = 2,ipph
     913           0 :          jc = ipp2 - j
     914           0 :          DO 180 k = 1,l1
     915           0 :             DO 170 i = 3,ido,2
     916           0 :                DO 160 m = 1,mp
     917           0 :                   c1(m,i-1,k,j) = ch(m,i-1,k,j) + ch(m,i-1,k,jc)
     918           0 :                   c1(m,i-1,k,jc) = ch(m,i,k,j) - ch(m,i,k,jc)
     919           0 :                   c1(m,i,k,j) = ch(m,i,k,j) + ch(m,i,k,jc)
     920           0 :                   c1(m,i,k,jc) = ch(m,i-1,k,jc) - ch(m,i-1,k,j)
     921           0 : 160            END DO
     922           0 : 170         END DO
     923           0 : 180      END DO
     924           0 : 190   END DO
     925           0 :       GO TO 280
     926           0 : 200   DO 240 j = 2,ipph
     927           0 :          jc = ipp2 - j
     928           0 :          DO 230 i = 3,ido,2
     929           0 :             DO 220 k = 1,l1
     930           0 :                DO 210 m = 1,mp
     931           0 :                   c1(m,i-1,k,j) = ch(m,i-1,k,j) + ch(m,i-1,k,jc)
     932           0 :                   c1(m,i-1,k,jc) = ch(m,i,k,j) - ch(m,i,k,jc)
     933           0 :                   c1(m,i,k,j) = ch(m,i,k,j) + ch(m,i,k,jc)
     934           0 :                   c1(m,i,k,jc) = ch(m,i-1,k,jc) - ch(m,i-1,k,j)
     935           0 : 210            END DO
     936           0 : 220         END DO
     937           0 : 230      END DO
     938           0 : 240   END DO
     939           0 :       GO TO 280
     940           0 : 250   DO 270 ik = 1,idl1
     941           0 :          DO 260 m = 1,mp
     942           0 :             c2(m,ik,1) = ch2(m,ik,1)
     943           0 : 260      END DO
     944           0 : 270   END DO
     945           0 : 280   DO 310 j = 2,ipph
     946           0 :          jc = ipp2 - j
     947           0 :          DO 300 k = 1,l1
     948           0 :             DO 290 m = 1,mp
     949           0 :                c1(m,1,k,j) = ch(m,1,k,j) + ch(m,1,k,jc)
     950           0 :                c1(m,1,k,jc) = ch(m,1,k,jc) - ch(m,1,k,j)
     951           0 : 290         END DO
     952           0 : 300      END DO
     953           0 : 310   END DO
     954             : 
     955             :       ar1 = 1.
     956             :       ai1 = 0.
     957           0 :       DO 370 l = 2,ipph
     958           0 :          lc = ipp2 - l
     959           0 :          ar1h = dcp*ar1 - dsp*ai1
     960           0 :          ai1 = dcp*ai1 + dsp*ar1
     961           0 :          ar1 = ar1h
     962           0 :          DO 330 ik = 1,idl1
     963           0 :             DO 320 m = 1,mp
     964           0 :                ch2(m,ik,l) = c2(m,ik,1) + ar1*c2(m,ik,2)
     965           0 :                ch2(m,ik,lc) = ai1*c2(m,ik,ip)
     966           0 : 320         END DO
     967           0 : 330      END DO
     968             :          dc2 = ar1
     969             :          ds2 = ai1
     970             :          ar2 = ar1
     971             :          ai2 = ai1
     972           0 :          DO 360 j = 3,ipph
     973           0 :             jc = ipp2 - j
     974           0 :             ar2h = dc2*ar2 - ds2*ai2
     975           0 :             ai2 = dc2*ai2 + ds2*ar2
     976           0 :             ar2 = ar2h
     977           0 :             DO 350 ik = 1,idl1
     978           0 :                DO 340 m = 1,mp
     979           0 :                   ch2(m,ik,l) = ch2(m,ik,l) + ar2*c2(m,ik,j)
     980           0 :                   ch2(m,ik,lc) = ch2(m,ik,lc) + ai2*c2(m,ik,jc)
     981           0 : 340            END DO
     982           0 : 350         END DO
     983           0 : 360      END DO
     984           0 : 370   END DO
     985           0 :       DO 400 j = 2,ipph
     986           0 :          DO 390 ik = 1,idl1
     987           0 :             DO 380 m = 1,mp
     988           0 :                ch2(m,ik,1) = ch2(m,ik,1) + c2(m,ik,j)
     989           0 : 380         END DO
     990           0 : 390      END DO
     991           0 : 400   END DO
     992             : 
     993           0 :       IF (ido < l1) GO TO 440
     994           0 :       DO 430 k = 1,l1
     995           0 :          DO 420 i = 1,ido
     996           0 :             DO 410 m = 1,mp
     997           0 :                cc(m,i,1,k) = ch(m,i,k,1)
     998           0 : 410         END DO
     999           0 : 420      END DO
    1000           0 : 430   END DO
    1001           0 :       GO TO 480
    1002           0 : 440   DO 470 i = 1,ido
    1003           0 :          DO 460 k = 1,l1
    1004           0 :             DO 450 m = 1,mp
    1005           0 :                cc(m,i,1,k) = ch(m,i,k,1)
    1006           0 : 450         END DO
    1007           0 : 460      END DO
    1008           0 : 470   END DO
    1009           0 : 480   DO 510 j = 2,ipph
    1010           0 :          jc = ipp2 - j
    1011           0 :          j2 = j + j
    1012           0 :          DO 500 k = 1,l1
    1013           0 :             DO 490 m = 1,mp
    1014           0 :                cc(m,ido,j2-2,k) = ch(m,1,k,j)
    1015           0 :                cc(m,1,j2-1,k) = ch(m,1,k,jc)
    1016           0 : 490         END DO
    1017           0 : 500      END DO
    1018           0 : 510   END DO
    1019           0 :       IF (ido == 1) RETURN
    1020           0 :       IF (nbd < l1) GO TO 560
    1021           0 :       DO 550 j = 2,ipph
    1022           0 :          jc = ipp2 - j
    1023           0 :          j2 = j + j
    1024           0 :          DO 540 k = 1,l1
    1025           0 :             DO 530 i = 3,ido,2
    1026           0 :                ic = idp2 - i
    1027           0 :                DO 520 m = 1,mp
    1028           0 :                   cc(m,i-1,j2-1,k) = ch(m,i-1,k,j) + ch(m,i-1,k,jc)
    1029           0 :                   cc(m,ic-1,j2-2,k) = ch(m,i-1,k,j) - ch(m,i-1,k,jc)
    1030           0 :                   cc(m,i,j2-1,k) = ch(m,i,k,j) + ch(m,i,k,jc)
    1031           0 :                   cc(m,ic,j2-2,k) = ch(m,i,k,jc) - ch(m,i,k,j)
    1032           0 : 520            END DO
    1033           0 : 530         END DO
    1034           0 : 540      END DO
    1035           0 : 550   END DO
    1036           0 :       RETURN
    1037           0 : 560   DO 600 j = 2,ipph
    1038           0 :          jc = ipp2 - j
    1039           0 :          j2 = j + j
    1040           0 :          DO 590 i = 3,ido,2
    1041           0 :             ic = idp2 - i
    1042           0 :             DO 580 k = 1,l1
    1043           0 :                DO 570 m = 1,mp
    1044           0 :                   cc(m,i-1,j2-1,k) = ch(m,i-1,k,j) + ch(m,i-1,k,jc)
    1045           0 :                   cc(m,ic-1,j2-2,k) = ch(m,i-1,k,j) - ch(m,i-1,k,jc)
    1046           0 :                   cc(m,i,j2-1,k) = ch(m,i,k,j) + ch(m,i,k,jc)
    1047           0 :                   cc(m,ic,j2-2,k) = ch(m,i,k,jc) - ch(m,i,k,j)
    1048           0 : 570            END DO
    1049           0 : 580         END DO
    1050           0 : 590      END DO
    1051           0 : 600   END DO
    1052             :       RETURN
    1053             :    END subroutine
    1054           0 :    SUBROUTINE vrftf1(m,n,c,ch,mdimc,wa,fac)
    1055             : 
    1056             : !     VRFFTPK, VERSION 1, AUGUST 1985
    1057             : 
    1058             :       DIMENSION ch(mdimc,n),c(mdimc,n),wa(n),fac(15)
    1059             : 
    1060           0 :       nf = fac(2)
    1061           0 :       na = 1
    1062           0 :       l2 = n
    1063           0 :       iw = n
    1064           0 :       DO 110 k1 = 1,nf
    1065           0 :          kh = nf - k1
    1066           0 :          ip = fac(kh+3)
    1067           0 :          l1 = l2/ip
    1068           0 :          ido = n/l2
    1069           0 :          idl1 = ido*l1
    1070           0 :          iw = iw - (ip-1)*ido
    1071           0 :          na = 1 - na
    1072           0 :          IF (ip /= 4) GO TO 20
    1073           0 :          ix2 = iw + ido
    1074           0 :          ix3 = ix2 + ido
    1075           0 :          IF (na /= 0) GO TO 10
    1076           0 :          CALL vradf4(m,ido,l1,c,ch,mdimc,wa(iw),wa(ix2),wa(ix3))
    1077           0 :          GO TO 100
    1078           0 : 10       CALL vradf4(m,ido,l1,ch,c,mdimc,wa(iw),wa(ix2),wa(ix3))
    1079           0 :          GO TO 100
    1080           0 : 20       IF (ip /= 2) GO TO 40
    1081           0 :          IF (na /= 0) GO TO 30
    1082           0 :          CALL vradf2(m,ido,l1,c,ch,mdimc,wa(iw))
    1083           0 :          GO TO 100
    1084           0 : 30       CALL vradf2(m,ido,l1,ch,c,mdimc,wa(iw))
    1085           0 :          GO TO 100
    1086           0 : 40       IF (ip /= 3) GO TO 60
    1087           0 :          ix2 = iw + ido
    1088           0 :          IF (na /= 0) GO TO 50
    1089           0 :          CALL vradf3(m,ido,l1,c,ch,mdimc,wa(iw),wa(ix2))
    1090           0 :          GO TO 100
    1091           0 : 50       CALL vradf3(m,ido,l1,ch,c,mdimc,wa(iw),wa(ix2))
    1092           0 :          GO TO 100
    1093           0 : 60       IF (ip /= 5) GO TO 80
    1094           0 :          ix2 = iw + ido
    1095           0 :          ix3 = ix2 + ido
    1096           0 :          ix4 = ix3 + ido
    1097           0 :          IF (na /= 0) GO TO 70
    1098           0 :          CALL vradf5(m,ido,l1,c,ch,mdimc,wa(iw),wa(ix2),wa(ix3),wa(ix4))
    1099           0 :          GO TO 100
    1100           0 : 70       CALL vradf5(m,ido,l1,ch,c,mdimc,wa(iw),wa(ix2),wa(ix3),wa(ix4))
    1101           0 :          GO TO 100
    1102           0 : 80       IF (ido == 1) na = 1 - na
    1103           0 :          IF (na /= 0) GO TO 90
    1104           0 :          CALL vradfg(m,ido,ip,l1,idl1,c,c,c,ch,ch,mdimc,wa(iw))
    1105           0 :          na = 1
    1106           0 :          GO TO 100
    1107           0 : 90       CALL vradfg(m,ido,ip,l1,idl1,ch,ch,ch,c,c,mdimc,wa(iw))
    1108           0 :          na = 0
    1109           0 : 100      l2 = l1
    1110           0 : 110   END DO
    1111           0 :       scale = sqrt(1./n)
    1112           0 :       IF (na == 1) GO TO 140
    1113           0 :       DO 130 j = 1,n
    1114           0 :          DO 120 i = 1,m
    1115           0 :             c(i,j) = scale*ch(i,j)
    1116           0 : 120      END DO
    1117           0 : 130   END DO
    1118           0 :       RETURN
    1119           0 : 140   DO 160 j = 1,n
    1120           0 :          DO 150 i = 1,m
    1121           0 :             c(i,j) = scale*c(i,j)
    1122           0 : 150      END DO
    1123           0 : 160   END DO
    1124             :       RETURN
    1125             :    END subroutine
    1126             : 
    1127           0 :    SUBROUTINE vrfftb(m,n,r,rt,mdimr,wsave)
    1128             : !***BEGIN PROLOGUE  VRFFTB
    1129             : !***DATE WRITTEN   850801   (YYMMDD)
    1130             : !***REVISION DATE  900509   (YYMMDD)
    1131             : !***CATEGORY NO.  J1A1
    1132             : !***KEYWORDS  FAST FOURIER TRANSFORM, REAL PERIODIC TRANSFORM,
    1133             : !             FOURIER SYNTHESIS, BACKWARD TRANSFORM, MULTIPLE SEQUENCES
    1134             : !***AUTHOR  SWEET, R.A. (NIST) AND LINDGREN, L.L. (NIST)
    1135             : !***PURPOSE  Backward real periodic transform, M sequences.
    1136             : !***DESCRIPTION
    1137             : 
    1138             : !  Subroutine VRFFTB computes the synthesis (backward transform) of a
    1139             : !  number of real periodic sequences from their Fourier coefficients.
    1140             : !  Specifically, for each set of independent Fourier coefficients
    1141             : !  F(K), the corresponding real periodic sequence is computed.
    1142             : 
    1143             : !  The array WSAVE which is used by subroutine VRFFTB must be
    1144             : !  initialized by calling subroutine VRFFTI(N,WSAVE).
    1145             : 
    1146             : !  Input Parameters
    1147             : 
    1148             : !  M       the number of sets of coefficients.
    1149             : 
    1150             : !  N       the length of the sequences of coefficients to be
    1151             : !          transformed.  The method is most efficient when N is a
    1152             : !          product of small primes, however n may be any positive
    1153             : !          integer.
    1154             : 
    1155             : !  R       areal two-dimensional array of size MDIMX x N containing the
    1156             : !          coefficients to be transformed.  Each set of coefficients
    1157             : !          F(K), K\0,1,..,N-1, is stored as a ROW of R.  Specifically,
    1158             : !          the I-th set of independent Fourier coefficients is stored
    1159             : 
    1160             : !                R(I,1) = REAL( F(I,0) ),
    1161             : 
    1162             : !                R(I,2*K) = REAL( F(I,K) )
    1163             : 
    1164             : !                R(I,2*K+1) = IMAG( F(I,K) )
    1165             : 
    1166             : !                   for K = 1, 2, . . . , M-1,
    1167             : 
    1168             : !                and, when N is even,
    1169             : 
    1170             : !                R(I,N) = REAL( F(I,N/2) ).
    1171             : 
    1172             : !  RT      a real two-dimensional work array of size MDIMX x N.
    1173             : 
    1174             : !  MDIMR   the row (or first) dimension of the arrays R and RT exactly
    1175             : !          as they appear in the calling program.  This parameter is
    1176             : !          used to specify the variable dimension of these arrays.
    1177             : 
    1178             : !  WSAVE   a real one-dimensional work array which must be dimensioned
    1179             : !          at least N+15.  The WSAVE array must be initialized by
    1180             : !          calling subroutine VRFFTI.  A different WSAVE array must be
    1181             : !          used for each different value of N.  This initialization does
    1182             : !          not have to be repeated so long as N remains unchanged.  The
    1183             : !          same WSAVE array may be used by VRFFTB and VRFFTB.
    1184             : 
    1185             : !  Output Parameters
    1186             : 
    1187             : !  R       contains M real periodic sequences corresponding to the given
    1188             : !          coefficients.  Specifically, the I-th row of R contains the
    1189             : !          real periodic sequence corresponding to the I-th set of
    1190             : !          independent Fourier coefficients F(I,K) stored as
    1191             : 
    1192             : !               R(I,J) = X(I,J-1) ,   J = 1, 2, . . . , N, where
    1193             : 
    1194             : !               X(I,J) = SQRT(1/N)* F(I,0) + (-1)**J*F(I,N/2)
    1195             : !                        + 2*SUM(K=1,M)[ REAL(F(I,2K))*COS(2K*J*PI/N)
    1196             : !                        - IMAG(F(I,2K+1))*SIN(2K*J*PI/N) ]  ,
    1197             : 
    1198             : !                 when N is even, and
    1199             : 
    1200             : !               X(I,J) = SQRT(1/N)* F(I,0) +
    1201             : !                        2*SUM(K=1,M)[ REAL(F(I,2K))*COS(2K*J*PI/N)
    1202             : !                        - IMAG(F(I,2K+1))*SIN(2K*J*PI/N) ]  ,
    1203             : 
    1204             : !                 when N is odd.
    1205             : 
    1206             : !  WSAVE   contains results which must not be destroyed between calls
    1207             : !          to VRFFTF or VRFFTB.
    1208             : 
    1209             : !  -----------------------------------------------------------------
    1210             : 
    1211             : !  NOTE  -  A call of VRFFTF followed immediately by a call of
    1212             : !           of VRFFTB will return the original sequences R.  Thus,
    1213             : !           VRFFTB is the correctly normalized inverse of VRFFTF.
    1214             : 
    1215             : !  -----------------------------------------------------------------
    1216             : 
    1217             : !  VRFFTB is a straightforward extension of the subprogram RFFTB to
    1218             : !  handle M simultaneous sequences.  RFFTB was originally developed
    1219             : !  by P. N. Swarztrauber of NCAR.
    1220             : 
    1221             : !              * * * * * * * * * * * * * * * * * * * * *
    1222             : !              *                                       *
    1223             : !              *         PROGRAM SPECIFICATIONS        *
    1224             : !              *                                       *
    1225             : !              * * * * * * * * * * * * * * * * * * * * *
    1226             : 
    1227             : !     Dimension of    R(MDIMR,N), RT(MDIMR,N), WSAVE(N+15)
    1228             : !     Arguments
    1229             : 
    1230             : !     Latest          AUGUST 1, 1985
    1231             : !     Revision
    1232             : 
    1233             : !     Subprograms     VRFFTI, VRFTI1, VRFFTF, VRFTF1, VRADF2, VRADF3,
    1234             : !     required        VRADF4, VRADF5, VRADFG, VRFFTB, VRFTB1, VRADB2,
    1235             : !                     VRADB3, VRADB4, VRADB5, VRADBG, PIMACH
    1236             : 
    1237             : !     Special         NONE
    1238             : !     Conditions
    1239             : 
    1240             : !     Common          NONE
    1241             : !     blocks
    1242             : 
    1243             : !     I/O             NONE
    1244             : 
    1245             : !     Precision       SINGLE
    1246             : 
    1247             : !     Specialist      ROLAND SWEET
    1248             : 
    1249             : !     Language        FORTRAN
    1250             : 
    1251             : !     History         WRITTEN BY LINDA LINDGREN AND ROLAND SWEET AT THE
    1252             : !                     NATIONAL BUREAU OF STANDARDS (BOULDER).
    1253             : 
    1254             : !     Algorithm       A REAL VARIANT OF THE STOCKHAM AUTOSORT VERSION
    1255             : !                     OF THE COOLEY-TUKEY FAST FOURIER TRANSFORM.
    1256             : 
    1257             : !     Portability     AMERICAN NATIONAL STANDARDS INSTITUTE FORTRAN 77.
    1258             : !                     THE ONLY MACHINE DEPENDENT CONSTANT IS LOCATED IN
    1259             : !                     THE FUNCTION PIMACH.
    1260             : 
    1261             : !     Required        COS,SIN
    1262             : !     resident
    1263             : !     Routines
    1264             : 
    1265             : !***REFERENCES  P. N. Swarztrauber, Vectorizing the FFTs, in Parallel
    1266             : !               Computations, (G. Rodrigue, ed.), Academic Press, 1982,
    1267             : !               pp. 51-83.
    1268             : !***ROUTINES CALLED  VRFTB1
    1269             : !***END PROLOGUE  VRFFTB
    1270             : 
    1271             : !     VRFFTPK, VERSION 1, AUGUST 1985
    1272             : 
    1273             :       IMPLICIT NONE
    1274             :       INTEGER, INTENT(IN) :: n, m, mdimr
    1275             :       REAL :: r(mdimr,n),rt(mdimr,n),wsave(n+15)
    1276             : 
    1277           0 :       IF (n == 1) RETURN
    1278           0 :       CALL vrftb1(m,n,r,rt,mdimr,wsave(1),wsave(n+1))
    1279           0 :       RETURN
    1280             : 
    1281             :    CONTAINS
    1282             : 
    1283           0 :       SUBROUTINE vradb2(mp,ido,l1,cc,ch,mdimc,wa1)
    1284             : 
    1285             : !     VRFFTPK, VERSION 1, AUGUST 1985
    1286             : 
    1287             :          IMPLICIT NONE
    1288             :          INTEGER, INTENT(IN) :: mp, ido, l1, mdimc
    1289             :          REAL, INTENT(IN)    :: cc(mdimc,ido,2,l1), wa1(ido)
    1290             :          REAL, INTENT(INOUT) :: ch(mdimc,ido,l1,2)
    1291             : 
    1292             :          INTEGER :: i, m, k, ic, idp2
    1293             : 
    1294           0 :          DO 20 k = 1,l1
    1295           0 :             DO 10 m = 1,mp
    1296           0 :                ch(m,1,k,1) = cc(m,1,1,k) + cc(m,ido,2,k)
    1297           0 :                ch(m,1,k,2) = cc(m,1,1,k) - cc(m,ido,2,k)
    1298           0 : 10          END DO
    1299           0 : 20       END DO
    1300           0 :          IF ( ido ==  2 ) THEN
    1301             :             GOTO 70
    1302           0 :          ELSEIF ( ido < 2 ) THEN
    1303             :             GOTO 100
    1304             :          ENDIF
    1305           0 :          idp2 = ido + 2
    1306           0 :          DO 60 k = 1,l1
    1307           0 :             DO 50 i = 3,ido,2
    1308           0 :                ic = idp2 - i
    1309           0 :                DO 40 m = 1,mp
    1310           0 :                   ch(m,i-1,k,1) = cc(m,i-1,1,k) + cc(m,ic-1,2,k)
    1311           0 :                   ch(m,i,k,1) = cc(m,i,1,k) - cc(m,ic,2,k)
    1312             :                   ch(m,i-1,k,2) = wa1(i-2)* (cc(m,i-1,1,k)- &
    1313             :                                              cc(m,ic-1,2,k)) - wa1(i-1)* &
    1314           0 :                                   (cc(m,i,1,k)+cc(m,ic,2,k))
    1315             :                   ch(m,i,k,2) = wa1(i-2)* (cc(m,i,1,k)+cc(m,ic,2,k)) + &
    1316           0 :                                 wa1(i-1)* (cc(m,i-1,1,k)-cc(m,ic-1,2,k))
    1317           0 : 40             END DO
    1318           0 : 50          END DO
    1319           0 : 60       END DO
    1320           0 :          IF (mod(ido,2) == 1) RETURN
    1321           0 : 70       DO 90 k = 1,l1
    1322           0 :             DO 80 m = 1,mp
    1323           0 :                ch(m,ido,k,1) = cc(m,ido,1,k) + cc(m,ido,1,k)
    1324           0 :                ch(m,ido,k,2) = - (cc(m,1,2,k)+cc(m,1,2,k))
    1325           0 : 80          END DO
    1326           0 : 90       END DO
    1327             : 100      RETURN
    1328             :       END SUBROUTINE vradb2
    1329             : 
    1330           0 :       SUBROUTINE vradb3(mp,ido,l1,cc,ch,mdimc,wa1,wa2)
    1331             : 
    1332             : !     VRFFTPK, VERSION 1, AUGUST 1985
    1333             : 
    1334             :          USE m_constants, ONLY : pimach
    1335             :          IMPLICIT NONE
    1336             :          INTEGER, INTENT(IN) :: mp, ido, l1, mdimc
    1337             :          REAL, INTENT(IN)    :: cc(mdimc,ido,3,l1), wa1(ido), wa2(ido)
    1338             :          REAL, INTENT(INOUT) :: ch(mdimc,ido,l1,3)
    1339             : 
    1340             :          INTEGER :: i, k, idp2, ic, m
    1341             :          REAL :: arg, taur, taui
    1342             : 
    1343           0 :          arg = 2.*pimach()/3.
    1344           0 :          taur = cos(arg)
    1345           0 :          taui = sin(arg)
    1346           0 :          DO 20 k = 1,l1
    1347           0 :             DO 10 m = 1,mp
    1348           0 :                ch(m,1,k,1) = cc(m,1,1,k) + 2.*cc(m,ido,2,k)
    1349             :                ch(m,1,k,2) = cc(m,1,1,k) + (2.*taur)*cc(m,ido,2,k) - &
    1350           0 :                              (2.*taui)*cc(m,1,3,k)
    1351             :                ch(m,1,k,3) = cc(m,1,1,k) + (2.*taur)*cc(m,ido,2,k) + &
    1352           0 :                &                     2.*taui*cc(m,1,3,k)
    1353           0 : 10          END DO
    1354           0 : 20       END DO
    1355           0 :          IF (ido == 1) RETURN
    1356           0 :          idp2 = ido + 2
    1357           0 :          DO 50 k = 1,l1
    1358           0 :             DO 40 i = 3,ido,2
    1359           0 :                ic = idp2 - i
    1360           0 :                DO 30 m = 1,mp
    1361             :                   ch(m,i-1,k,1) = cc(m,i-1,1,k) + &
    1362           0 :                                   (cc(m,i-1,3,k)+cc(m,ic-1,2,k))
    1363           0 :                   ch(m,i,k,1) = cc(m,i,1,k) + (cc(m,i,3,k)-cc(m,ic,2,k))
    1364             :                   ch(m,i-1,k,2) = wa1(i-2)* ((cc(m,i-1,1,k)+taur* (cc(m, &
    1365             :                                                                       i-1,3,k)+cc(m,ic-1,2,k)))- &
    1366             :                                              (taui* (cc(m,i,3,k)+cc(m,ic,2,k)))) - &
    1367             :                                   wa1(i-1)* ((cc(m,i,1,k)+taur* (cc(m,i,3, &
    1368             :                                                                     k)-cc(m,ic,2,k)))+ (taui* (cc(m,i-1,3, &
    1369           0 :                                                                                                   k)-cc(m,ic-1,2,k))))
    1370             :                   ch(m,i,k,2) = wa1(i-2)* ((cc(m,i,1,k)+taur* (cc(m,i,3, &
    1371             :                   k)-cc(m,ic,2,k)))+ (taui* (cc(m,i-1,3, &
    1372             :                   k)-cc(m,ic-1,2,k)))) + &
    1373             :                   wa1(i-1)* ((cc(m,i-1,1,k)+taur* (cc(m,i-1, &
    1374             :                   &                        3,k)+cc(m,ic-1,2,k)))- &
    1375           0 :                   (taui* (cc(m,i,3,k)+cc(m,ic,2,k))))
    1376             :                   ch(m,i-1,k,3) = wa2(i-2)* ((cc(m,i-1,1,k)+taur* (cc(m, &
    1377             :                                                                       i-1,3,k)+cc(m,ic-1,2,k)))+ &
    1378             :                                              (taui* (cc(m,i,3,k)+cc(m,ic,2,k)))) - &
    1379             :                                   wa2(i-1)* ((cc(m,i,1,k)+taur* (cc(m,i,3, &
    1380             :                                                                     k)-cc(m,ic,2,k)))- (taui* (cc(m,i-1,3, &
    1381           0 :                                                                                                   k)-cc(m,ic-1,2,k))))
    1382             :                   ch(m,i,k,3) = wa2(i-2)* ((cc(m,i,1,k)+taur* (cc(m,i,3, &
    1383             :                   k)-cc(m,ic,2,k)))- (taui* (cc(m,i-1,3, &
    1384             :                   k)-cc(m,ic-1,2,k)))) + &
    1385             :                   wa2(i-1)* ((cc(m,i-1,1,k)+taur* (cc(m,i-1, &
    1386             :                   &                        3,k)+cc(m,ic-1,2,k)))+ &
    1387           0 :                   (taui* (cc(m,i,3,k)+cc(m,ic,2,k))))
    1388           0 : 30             END DO
    1389           0 : 40          END DO
    1390           0 : 50       END DO
    1391             :          RETURN
    1392             :       END SUBROUTINE vradb3
    1393             : 
    1394           0 :       SUBROUTINE vradb4(mp,ido,l1,cc,ch,mdimc,wa1,wa2,wa3)
    1395             : 
    1396             : !     VRFFTPK, VERSION 1, AUGUST 1985
    1397             : 
    1398             :          IMPLICIT NONE
    1399             :          INTEGER, INTENT(IN) :: mp, ido, l1, mdimc
    1400             :          REAL, INTENT(IN)    :: cc(mdimc,ido,4,l1), wa1(ido), wa2(ido), &
    1401             :                                 wa3(ido)
    1402             :          REAL, INTENT(INOUT) :: ch(mdimc,ido,l1,4)
    1403             : 
    1404             :          INTEGER :: k, m, i, idp2, ic
    1405             :          REAL :: sqrt2
    1406             : 
    1407           0 :          sqrt2 = sqrt(2.)
    1408           0 :          DO 20 k = 1,l1
    1409           0 :             DO 10 m = 1,mp
    1410             :                ch(m,1,k,3) = (cc(m,1,1,k)+cc(m,ido,4,k)) - &
    1411           0 :                              (cc(m,ido,2,k)+cc(m,ido,2,k))
    1412             :                ch(m,1,k,1) = (cc(m,1,1,k)+cc(m,ido,4,k)) + &
    1413           0 :                              (cc(m,ido,2,k)+cc(m,ido,2,k))
    1414             :                ch(m,1,k,4) = (cc(m,1,1,k)-cc(m,ido,4,k)) + &
    1415           0 :                              (cc(m,1,3,k)+cc(m,1,3,k))
    1416             :                ch(m,1,k,2) = (cc(m,1,1,k)-cc(m,ido,4,k)) - &
    1417           0 :                              (cc(m,1,3,k)+cc(m,1,3,k))
    1418           0 : 10          END DO
    1419           0 : 20       END DO
    1420           0 :          IF ( ido ==  2 ) THEN
    1421             :             GOTO 70
    1422           0 :          ELSEIF ( ido < 2 ) THEN
    1423             :             GOTO 100
    1424             :          ENDIF
    1425           0 :          idp2 = ido + 2
    1426           0 :          DO 60 k = 1,l1
    1427           0 :             DO 50 i = 3,ido,2
    1428           0 :                ic = idp2 - i
    1429           0 :                DO 40 m = 1,mp
    1430             :                   ch(m,i-1,k,1) = (cc(m,i-1,1,k)+cc(m,ic-1,4,k)) + &
    1431           0 :                                   (cc(m,i-1,3,k)+cc(m,ic-1,2,k))
    1432             :                   ch(m,i,k,1) = (cc(m,i,1,k)-cc(m,ic,4,k)) + &
    1433           0 :                                 (cc(m,i,3,k)-cc(m,ic,2,k))
    1434             :                   ch(m,i-1,k,2) = wa1(i-2)* ((cc(m,i-1,1,k)-cc(m,ic-1,4, &
    1435             :                                                                k))- (cc(m,i,3,k)+cc(m,ic,2,k))) - &
    1436             :                                   wa1(i-1)* ((cc(m,i,1,k)+cc(m,ic,4,k))+ &
    1437           0 :                                              (cc(m,i-1,3,k)-cc(m,ic-1,2,k)))
    1438             :                   ch(m,i,k,2) = wa1(i-2)* ((cc(m,i,1,k)+cc(m,ic,4,k))+ &
    1439             :                                            (cc(m,i-1,3,k)-cc(m,ic-1,2,k))) + &
    1440             :                                 wa1(i-1)* ((cc(m,i-1,1,k)-cc(m,ic-1,4,k))- &
    1441           0 :                                            (cc(m,i,3,k)+cc(m,ic,2,k)))
    1442             :                   ch(m,i-1,k,3) = wa2(i-2)* ((cc(m,i-1,1,k)+cc(m,ic-1,4, &
    1443             :                                                                k))- (cc(m,i-1,3,k)+cc(m,ic-1,2,k))) - &
    1444             :                                   wa2(i-1)* ((cc(m,i,1,k)-cc(m,ic,4,k))- &
    1445           0 :                                              (cc(m,i,3,k)-cc(m,ic,2,k)))
    1446             :                   ch(m,i,k,3) = wa2(i-2)* ((cc(m,i,1,k)-cc(m,ic,4,k))- &
    1447             :                                            (cc(m,i,3,k)-cc(m,ic,2,k))) + &
    1448             :                                 wa2(i-1)* ((cc(m,i-1,1,k)+cc(m,ic-1,4,k))- &
    1449           0 :                                            (cc(m,i-1,3,k)+cc(m,ic-1,2,k)))
    1450             :                   ch(m,i-1,k,4) = wa3(i-2)* ((cc(m,i-1,1,k)-cc(m,ic-1,4, &
    1451             :                                                                k))+ (cc(m,i,3,k)+cc(m,ic,2,k))) - &
    1452             :                                   wa3(i-1)* ((cc(m,i,1,k)+cc(m,ic,4,k))- &
    1453           0 :                                              (cc(m,i-1,3,k)-cc(m,ic-1,2,k)))
    1454             :                   ch(m,i,k,4) = wa3(i-2)* ((cc(m,i,1,k)+cc(m,ic,4,k))- &
    1455             :                                            (cc(m,i-1,3,k)-cc(m,ic-1,2,k))) + &
    1456             :                                 wa3(i-1)* ((cc(m,i-1,1,k)-cc(m,ic-1,4,k))+ &
    1457           0 :                                            (cc(m,i,3,k)+cc(m,ic,2,k)))
    1458           0 : 40             END DO
    1459           0 : 50          END DO
    1460           0 : 60       END DO
    1461           0 :          IF (mod(ido,2) == 1) RETURN
    1462             : 70       CONTINUE
    1463           0 :          DO 90 k = 1,l1
    1464           0 :             DO 80 m = 1,mp
    1465             :                ch(m,ido,k,1) = (cc(m,ido,1,k)+cc(m,ido,3,k)) + &
    1466           0 :                                (cc(m,ido,1,k)+cc(m,ido,3,k))
    1467             :                ch(m,ido,k,2) = sqrt2* ((cc(m,ido,1,k)-cc(m,ido,3,k))- &
    1468           0 :                                        (cc(m,1,2,k)+cc(m,1,4,k)))
    1469             :                ch(m,ido,k,3) = (cc(m,1,4,k)-cc(m,1,2,k)) + &
    1470           0 :                                (cc(m,1,4,k)-cc(m,1,2,k))
    1471             :                ch(m,ido,k,4) = -sqrt2* ((cc(m,ido,1,k)-cc(m,ido,3,k))+ &
    1472           0 :                                         (cc(m,1,2,k)+cc(m,1,4,k)))
    1473           0 : 80          END DO
    1474           0 : 90       END DO
    1475             : 100      RETURN
    1476             :       END SUBROUTINE vradb4
    1477             : 
    1478           0 :       SUBROUTINE vradb5(mp,ido,l1,cc,ch,mdimc,wa1,wa2,wa3,wa4)
    1479             : 
    1480             : !     VRFFTPK, VERSION 1, AUGUST 1985
    1481             : 
    1482             :          USE m_constants, ONLY : pimach
    1483             :          IMPLICIT NONE
    1484             :          INTEGER, INTENT(IN) :: mp, ido, l1, mdimc
    1485             :          REAL, INTENT(IN)    :: cc(mdimc,ido,5,l1), wa1(ido), wa2(ido), &
    1486             :                                 wa3(ido),wa4(ido)
    1487             :          REAL, INTENT(INOUT) :: ch(mdimc,ido,l1,5)
    1488             : 
    1489             :          INTEGER :: i, k, m, ic, idp2
    1490             :          REAL :: arg, tr11, ti11, tr12, ti12
    1491             : 
    1492           0 :          arg = 2.*pimach()/5.
    1493           0 :          tr11 = cos(arg)
    1494           0 :          ti11 = sin(arg)
    1495           0 :          tr12 = cos(2.*arg)
    1496           0 :          ti12 = sin(2.*arg)
    1497           0 :          DO 20 k = 1,l1
    1498           0 :             DO 10 m = 1,mp
    1499             :                ch(m,1,k,1) = cc(m,1,1,k) + 2.*cc(m,ido,2,k) + &
    1500           0 :                &                     2.*cc(m,ido,4,k)
    1501             :                ch(m,1,k,2) = (cc(m,1,1,k)+tr11*2.*cc(m,ido,2,k)+ &
    1502             :                               tr12*2.*cc(m,ido,4,k)) - &
    1503           0 :                              (ti11*2.*cc(m,1,3,k)+ti12*2.*cc(m,1,5,k))
    1504             :                ch(m,1,k,3) = (cc(m,1,1,k)+tr12*2.*cc(m,ido,2,k)+ &
    1505             :                               tr11*2.*cc(m,ido,4,k)) - &
    1506           0 :                              (ti12*2.*cc(m,1,3,k)-ti11*2.*cc(m,1,5,k))
    1507             :                ch(m,1,k,4) = (cc(m,1,1,k)+tr12*2.*cc(m,ido,2,k)+ &
    1508             :                               tr11*2.*cc(m,ido,4,k)) + &
    1509           0 :                              (ti12*2.*cc(m,1,3,k)-ti11*2.*cc(m,1,5,k))
    1510             :                ch(m,1,k,5) = (cc(m,1,1,k)+tr11*2.*cc(m,ido,2,k)+ &
    1511             :                               tr12*2.*cc(m,ido,4,k)) + &
    1512           0 :                              (ti11*2.*cc(m,1,3,k)+ti12*2.*cc(m,1,5,k))
    1513           0 : 10          END DO
    1514           0 : 20       END DO
    1515           0 :          IF (ido == 1) RETURN
    1516           0 :          idp2 = ido + 2
    1517           0 :          DO 50 k = 1,l1
    1518           0 :             DO 40 i = 3,ido,2
    1519           0 :                ic = idp2 - i
    1520           0 :                DO 30 m = 1,mp
    1521             :                   ch(m,i-1,k,1) = cc(m,i-1,1,k) + &
    1522             :                                   (cc(m,i-1,3,k)+cc(m,ic-1,2,k)) + &
    1523           0 :                                   (cc(m,i-1,5,k)+cc(m,ic-1,4,k))
    1524             :                   ch(m,i,k,1) = cc(m,i,1,k) + (cc(m,i,3,k)-cc(m,ic,2,k)) + &
    1525           0 :                                 (cc(m,i,5,k)-cc(m,ic,4,k))
    1526             :                   ch(m,i-1,k,2) = wa1(i-2)* ((cc(m,i-1,1,k)+tr11* (cc(m, &
    1527             :                   i-1,3,k)+cc(m,ic-1,2,k))+tr12* (cc(m,i-1, &
    1528             :                   &                          5,k)+cc(m,ic-1,4,k)))- &
    1529             :                   (ti11* (cc(m,i,3,k)+cc(m,ic,2, &
    1530             :                   k))+ti12* (cc(m,i,5,k)+cc(m,ic,4,k)))) - &
    1531             :                   wa1(i-1)* ((cc(m,i,1,k)+tr11* (cc(m,i,3, &
    1532             :                   k)-cc(m,ic,2,k))+tr12* (cc(m,i,5,k)-cc(m, &
    1533             :                   ic,4,k)))+ (ti11* (cc(m,i-1,3,k)-cc(m, &
    1534             :                   ic-1,2,k))+ti12* (cc(m,i-1,5,k)-cc(m, &
    1535           0 :                   ic-1,4,k))))
    1536             :                   ch(m,i,k,2) = wa1(i-2)* ((cc(m,i,1,k)+tr11* (cc(m,i,3, &
    1537             :                   k)-cc(m,ic,2,k))+tr12* (cc(m,i,5,k)-cc(m, &
    1538             :                   ic,4,k)))+ (ti11* (cc(m,i-1,3,k)-cc(m,ic-1, &
    1539             :                   &                        2,k))+ti12* (cc(m,i-1,5,k)-cc(m,ic-1,4, &
    1540             :                   k)))) + wa1(i-1)* ((cc(m,i-1,1, &
    1541             :                   k)+tr11* (cc(m,i-1,3,k)+cc(m,ic-1,2, &
    1542             :                   k))+tr12* (cc(m,i-1,5,k)+cc(m,ic-1,4,k)))- &
    1543             :                   (ti11* (cc(m,i,3,k)+cc(m,ic,2, &
    1544           0 :                   k))+ti12* (cc(m,i,5,k)+cc(m,ic,4,k))))
    1545             :                   ch(m,i-1,k,3) = wa2(i-2)* ((cc(m,i-1,1,k)+tr12* (cc(m, &
    1546             :                   i-1,3,k)+cc(m,ic-1,2,k))+tr11* (cc(m,i-1, &
    1547             :                   &                          5,k)+cc(m,ic-1,4,k)))- &
    1548             :                   (ti12* (cc(m,i,3,k)+cc(m,ic,2, &
    1549             :                   k))-ti11* (cc(m,i,5,k)+cc(m,ic,4,k)))) - &
    1550             :                   wa2(i-1)* ((cc(m,i,1,k)+tr12* (cc(m,i,3, &
    1551             :                   k)-cc(m,ic,2,k))+tr11* (cc(m,i,5,k)-cc(m, &
    1552             :                   ic,4,k)))+ (ti12* (cc(m,i-1,3,k)-cc(m, &
    1553             :                   ic-1,2,k))-ti11* (cc(m,i-1,5,k)-cc(m, &
    1554           0 :                   ic-1,4,k))))
    1555             :                   ch(m,i,k,3) = wa2(i-2)* ((cc(m,i,1,k)+tr12* (cc(m,i,3, &
    1556             :                   k)-cc(m,ic,2,k))+tr11* (cc(m,i,5,k)-cc(m, &
    1557             :                   ic,4,k)))+ (ti12* (cc(m,i-1,3,k)-cc(m,ic-1, &
    1558             :                   &                        2,k))-ti11* (cc(m,i-1,5,k)-cc(m,ic-1,4, &
    1559             :                   k)))) + wa2(i-1)* ((cc(m,i-1,1, &
    1560             :                   k)+tr12* (cc(m,i-1,3,k)+cc(m,ic-1,2, &
    1561             :                   k))+tr11* (cc(m,i-1,5,k)+cc(m,ic-1,4,k)))- &
    1562             :                   (ti12* (cc(m,i,3,k)+cc(m,ic,2, &
    1563           0 :                   k))-ti11* (cc(m,i,5,k)+cc(m,ic,4,k))))
    1564             :                   ch(m,i-1,k,4) = wa3(i-2)* ((cc(m,i-1,1,k)+tr12* (cc(m, &
    1565             :                   i-1,3,k)+cc(m,ic-1,2,k))+tr11* (cc(m,i-1, &
    1566             :                   &                          5,k)+cc(m,ic-1,4,k)))+ &
    1567             :                   (ti12* (cc(m,i,3,k)+cc(m,ic,2, &
    1568             :                   k))-ti11* (cc(m,i,5,k)+cc(m,ic,4,k)))) - &
    1569             :                   wa3(i-1)* ((cc(m,i,1,k)+tr12* (cc(m,i,3, &
    1570             :                   k)-cc(m,ic,2,k))+tr11* (cc(m,i,5,k)-cc(m, &
    1571             :                   ic,4,k)))- (ti12* (cc(m,i-1,3,k)-cc(m, &
    1572             :                   ic-1,2,k))-ti11* (cc(m,i-1,5,k)-cc(m, &
    1573           0 :                   ic-1,4,k))))
    1574             :                   ch(m,i,k,4) = wa3(i-2)* ((cc(m,i,1,k)+tr12* (cc(m,i,3, &
    1575             :                   k)-cc(m,ic,2,k))+tr11* (cc(m,i,5,k)-cc(m, &
    1576             :                   ic,4,k)))- (ti12* (cc(m,i-1,3,k)-cc(m,ic-1, &
    1577             :                   &                        2,k))-ti11* (cc(m,i-1,5,k)-cc(m,ic-1,4, &
    1578             :                   k)))) + wa3(i-1)* ((cc(m,i-1,1, &
    1579             :                   k)+tr12* (cc(m,i-1,3,k)+cc(m,ic-1,2, &
    1580             :                   k))+tr11* (cc(m,i-1,5,k)+cc(m,ic-1,4,k)))+ &
    1581             :                   (ti12* (cc(m,i,3,k)+cc(m,ic,2, &
    1582           0 :                   k))-ti11* (cc(m,i,5,k)+cc(m,ic,4,k))))
    1583             :                   ch(m,i-1,k,5) = wa4(i-2)* ((cc(m,i-1,1,k)+tr11* (cc(m, &
    1584             :                   i-1,3,k)+cc(m,ic-1,2,k))+tr12* (cc(m,i-1, &
    1585             :                   &                          5,k)+cc(m,ic-1,4,k)))+ &
    1586             :                   (ti11* (cc(m,i,3,k)+cc(m,ic,2, &
    1587             :                   k))+ti12* (cc(m,i,5,k)+cc(m,ic,4,k)))) - &
    1588             :                   wa4(i-1)* ((cc(m,i,1,k)+tr11* (cc(m,i,3, &
    1589             :                   k)-cc(m,ic,2,k))+tr12* (cc(m,i,5,k)-cc(m, &
    1590             :                   ic,4,k)))- (ti11* (cc(m,i-1,3,k)-cc(m, &
    1591             :                   ic-1,2,k))+ti12* (cc(m,i-1,5,k)-cc(m, &
    1592           0 :                   ic-1,4,k))))
    1593             :                   ch(m,i,k,5) = wa4(i-2)* ((cc(m,i,1,k)+tr11* (cc(m,i,3, &
    1594             :                   k)-cc(m,ic,2,k))+tr12* (cc(m,i,5,k)-cc(m, &
    1595             :                   ic,4,k)))- (ti11* (cc(m,i-1,3,k)-cc(m,ic-1, &
    1596             :                   &                        2,k))+ti12* (cc(m,i-1,5,k)-cc(m,ic-1,4, &
    1597             :                   k)))) + wa4(i-1)* ((cc(m,i-1,1, &
    1598             :                   k)+tr11* (cc(m,i-1,3,k)+cc(m,ic-1,2, &
    1599             :                   k))+tr12* (cc(m,i-1,5,k)+cc(m,ic-1,4,k)))+ &
    1600             :                   (ti11* (cc(m,i,3,k)+cc(m,ic,2, &
    1601           0 :                   k))+ti12* (cc(m,i,5,k)+cc(m,ic,4,k))))
    1602           0 : 30             END DO
    1603           0 : 40          END DO
    1604           0 : 50       END DO
    1605             :          RETURN
    1606             :       END SUBROUTINE vradb5
    1607             : 
    1608           0 :       SUBROUTINE vradbg(mp,ido,ip,l1,idl1,cc,c1,c2,ch,ch2, &
    1609           0 :                         mdimc,wa)
    1610             : 
    1611             : !     VRFFTPK, VERSION 1, AUGUST 1985
    1612             : 
    1613             :          USE m_constants, ONLY : pimach
    1614             :          IMPLICIT NONE
    1615             :          INTEGER, INTENT(IN) :: mp, ido, ip, l1, idl1, mdimc
    1616             :          REAL, INTENT(IN)    :: cc(mdimc,ido,ip,l1), wa(ido)
    1617             :          REAL, INTENT(INOUT) :: ch(mdimc,ido,l1,ip), ch2(mdimc,idl1,ip), &
    1618             :                                 c1(mdimc,ido,l1,ip), c2(mdimc,idl1,ip)
    1619             : 
    1620             :          INTEGER :: i, j, j2, k, l, m, ik, is, idp2, nbd, ipp2, ipph, &
    1621             :                     ic, jc, lc, idij
    1622             :          REAL :: ai1, ar1, ar2, ai2, ar1h, ar2h, tpi, arg, dcp, dsp, &
    1623             :                  dc2, ds2
    1624             : 
    1625           0 :          tpi = 2.*pimach()
    1626           0 :          arg = tpi/real(ip)
    1627           0 :          dcp = cos(arg)
    1628           0 :          dsp = sin(arg)
    1629           0 :          idp2 = ido + 2
    1630           0 :          nbd = (ido-1)/2
    1631           0 :          ipp2 = ip + 2
    1632           0 :          ipph = (ip+1)/2
    1633           0 :          IF (ido < l1) GO TO 40
    1634           0 :          DO 30 k = 1,l1
    1635           0 :             DO 20 i = 1,ido
    1636           0 :                DO 10 m = 1,mp
    1637           0 :                   ch(m,i,k,1) = cc(m,i,1,k)
    1638           0 : 10             END DO
    1639           0 : 20          END DO
    1640           0 : 30       END DO
    1641           0 :          GO TO 80
    1642           0 : 40       DO 70 i = 1,ido
    1643           0 :             DO 60 k = 1,l1
    1644           0 :                DO 50 m = 1,mp
    1645           0 :                   ch(m,i,k,1) = cc(m,i,1,k)
    1646           0 : 50             END DO
    1647           0 : 60          END DO
    1648           0 : 70       END DO
    1649           0 : 80       DO 110 j = 2,ipph
    1650           0 :             jc = ipp2 - j
    1651           0 :             j2 = j + j
    1652           0 :             DO 100 k = 1,l1
    1653           0 :                DO 90 m = 1,mp
    1654           0 :                   ch(m,1,k,j) = cc(m,ido,j2-2,k) + cc(m,ido,j2-2,k)
    1655           0 :                   ch(m,1,k,jc) = cc(m,1,j2-1,k) + cc(m,1,j2-1,k)
    1656           0 : 90             END DO
    1657           0 : 100         END DO
    1658           0 : 110      END DO
    1659           0 :          IF (ido == 1) GO TO 210
    1660           0 :          IF (nbd < l1) GO TO 160
    1661           0 :          DO 150 j = 2,ipph
    1662           0 :             jc = ipp2 - j
    1663           0 :             DO 140 k = 1,l1
    1664           0 :                DO 130 i = 3,ido,2
    1665           0 :                   ic = idp2 - i
    1666           0 :                   DO 120 m = 1,mp
    1667           0 :                      ch(m,i-1,k,j) = cc(m,i-1,2*j-1,k) + cc(m,ic-1,2*j-2,k)
    1668             :                      ch(m,i-1,k,jc) = cc(m,i-1,2*j-1,k) - &
    1669           0 :                                       cc(m,ic-1,2*j-2,k)
    1670           0 :                      ch(m,i,k,j) = cc(m,i,2*j-1,k) - cc(m,ic,2*j-2,k)
    1671           0 :                      ch(m,i,k,jc) = cc(m,i,2*j-1,k) + cc(m,ic,2*j-2,k)
    1672           0 : 120               END DO
    1673           0 : 130            END DO
    1674           0 : 140         END DO
    1675           0 : 150      END DO
    1676           0 :          GO TO 210
    1677           0 : 160      DO 200 j = 2,ipph
    1678           0 :             jc = ipp2 - j
    1679           0 :             DO 190 i = 3,ido,2
    1680           0 :                ic = idp2 - i
    1681           0 :                DO 180 k = 1,l1
    1682           0 :                   DO 170 m = 1,mp
    1683           0 :                      ch(m,i-1,k,j) = cc(m,i-1,2*j-1,k) + cc(m,ic-1,2*j-2,k)
    1684             :                      ch(m,i-1,k,jc) = cc(m,i-1,2*j-1,k) - &
    1685           0 :                                       cc(m,ic-1,2*j-2,k)
    1686           0 :                      ch(m,i,k,j) = cc(m,i,2*j-1,k) - cc(m,ic,2*j-2,k)
    1687           0 :                      ch(m,i,k,jc) = cc(m,i,2*j-1,k) + cc(m,ic,2*j-2,k)
    1688           0 : 170               END DO
    1689           0 : 180            END DO
    1690           0 : 190         END DO
    1691           0 : 200      END DO
    1692             : 210      ar1 = 1.
    1693             :          ai1 = 0.
    1694           0 :          DO 270 l = 2,ipph
    1695           0 :             lc = ipp2 - l
    1696           0 :             ar1h = dcp*ar1 - dsp*ai1
    1697           0 :             ai1 = dcp*ai1 + dsp*ar1
    1698           0 :             ar1 = ar1h
    1699           0 :             DO 230 ik = 1,idl1
    1700           0 :                DO 220 m = 1,mp
    1701           0 :                   c2(m,ik,l) = ch2(m,ik,1) + ar1*ch2(m,ik,2)
    1702           0 :                   c2(m,ik,lc) = ai1*ch2(m,ik,ip)
    1703           0 : 220            END DO
    1704           0 : 230         END DO
    1705             :             dc2 = ar1
    1706             :             ds2 = ai1
    1707             :             ar2 = ar1
    1708             :             ai2 = ai1
    1709           0 :             DO 260 j = 3,ipph
    1710           0 :                jc = ipp2 - j
    1711           0 :                ar2h = dc2*ar2 - ds2*ai2
    1712           0 :                ai2 = dc2*ai2 + ds2*ar2
    1713           0 :                ar2 = ar2h
    1714           0 :                DO 250 ik = 1,idl1
    1715           0 :                   DO 240 m = 1,mp
    1716           0 :                      c2(m,ik,l) = c2(m,ik,l) + ar2*ch2(m,ik,j)
    1717           0 :                      c2(m,ik,lc) = c2(m,ik,lc) + ai2*ch2(m,ik,jc)
    1718           0 : 240               END DO
    1719           0 : 250            END DO
    1720           0 : 260         END DO
    1721           0 : 270      END DO
    1722           0 :          DO 300 j = 2,ipph
    1723           0 :             DO 290 ik = 1,idl1
    1724           0 :                DO 280 m = 1,mp
    1725           0 :                   ch2(m,ik,1) = ch2(m,ik,1) + ch2(m,ik,j)
    1726           0 : 280            END DO
    1727           0 : 290         END DO
    1728           0 : 300      END DO
    1729           0 :          DO 330 j = 2,ipph
    1730           0 :             jc = ipp2 - j
    1731           0 :             DO 320 k = 1,l1
    1732           0 :                DO 310 m = 1,mp
    1733           0 :                   ch(m,1,k,j) = c1(m,1,k,j) - c1(m,1,k,jc)
    1734           0 :                   ch(m,1,k,jc) = c1(m,1,k,j) + c1(m,1,k,jc)
    1735           0 : 310            END DO
    1736           0 : 320         END DO
    1737           0 : 330      END DO
    1738           0 :          IF (ido == 1) GO TO 430
    1739           0 :          IF (nbd < l1) GO TO 380
    1740           0 :          DO 370 j = 2,ipph
    1741           0 :             jc = ipp2 - j
    1742           0 :             DO 360 k = 1,l1
    1743           0 :                DO 350 i = 3,ido,2
    1744           0 :                   DO 340 m = 1,mp
    1745           0 :                      ch(m,i-1,k,j) = c1(m,i-1,k,j) - c1(m,i,k,jc)
    1746           0 :                      ch(m,i-1,k,jc) = c1(m,i-1,k,j) + c1(m,i,k,jc)
    1747           0 :                      ch(m,i,k,j) = c1(m,i,k,j) + c1(m,i-1,k,jc)
    1748           0 :                      ch(m,i,k,jc) = c1(m,i,k,j) - c1(m,i-1,k,jc)
    1749           0 : 340               END DO
    1750           0 : 350            END DO
    1751           0 : 360         END DO
    1752           0 : 370      END DO
    1753           0 :          GO TO 430
    1754           0 : 380      DO 420 j = 2,ipph
    1755           0 :             jc = ipp2 - j
    1756           0 :             DO 410 i = 3,ido,2
    1757           0 :                DO 400 k = 1,l1
    1758           0 :                   DO 390 m = 1,mp
    1759           0 :                      ch(m,i-1,k,j) = c1(m,i-1,k,j) - c1(m,i,k,jc)
    1760           0 :                      ch(m,i-1,k,jc) = c1(m,i-1,k,j) + c1(m,i,k,jc)
    1761           0 :                      ch(m,i,k,j) = c1(m,i,k,j) + c1(m,i-1,k,jc)
    1762           0 :                      ch(m,i,k,jc) = c1(m,i,k,j) - c1(m,i-1,k,jc)
    1763           0 : 390               END DO
    1764           0 : 400            END DO
    1765           0 : 410         END DO
    1766           0 : 420      END DO
    1767             : 430      CONTINUE
    1768           0 :          IF (ido == 1) RETURN
    1769           0 :          DO 450 ik = 1,idl1
    1770           0 :             DO 440 m = 1,mp
    1771           0 :                c2(m,ik,1) = ch2(m,ik,1)
    1772           0 : 440         END DO
    1773           0 : 450      END DO
    1774           0 :          DO 480 j = 2,ip
    1775           0 :             DO 470 k = 1,l1
    1776           0 :                DO 460 m = 1,mp
    1777           0 :                   c1(m,1,k,j) = ch(m,1,k,j)
    1778           0 : 460            END DO
    1779           0 : 470         END DO
    1780           0 : 480      END DO
    1781           0 :          IF (nbd > l1) GO TO 530
    1782           0 :          is = -ido
    1783           0 :          DO 520 j = 2,ip
    1784           0 :             is = is + ido
    1785           0 :             idij = is
    1786           0 :             DO 510 i = 3,ido,2
    1787           0 :                idij = idij + 2
    1788           0 :                DO 500 k = 1,l1
    1789           0 :                   DO 490 m = 1,mp
    1790             :                      c1(m,i-1,k,j) = wa(idij-1)*ch(m,i-1,k,j) - &
    1791           0 :                                      wa(idij)*ch(m,i,k,j)
    1792             :                      c1(m,i,k,j) = wa(idij-1)*ch(m,i,k,j) + &
    1793           0 :                                    wa(idij)*ch(m,i-1,k,j)
    1794           0 : 490               END DO
    1795           0 : 500            END DO
    1796           0 : 510         END DO
    1797           0 : 520      END DO
    1798           0 :          GO TO 580
    1799           0 : 530      is = -ido
    1800           0 :          DO 570 j = 2,ip
    1801           0 :             is = is + ido
    1802           0 :             DO 560 k = 1,l1
    1803           0 :                idij = is
    1804           0 :                DO 550 i = 3,ido,2
    1805           0 :                   idij = idij + 2
    1806           0 :                   DO 540 m = 1,mp
    1807             :                      c1(m,i-1,k,j) = wa(idij-1)*ch(m,i-1,k,j) - &
    1808           0 :                                      wa(idij)*ch(m,i,k,j)
    1809             :                      c1(m,i,k,j) = wa(idij-1)*ch(m,i,k,j) + &
    1810           0 :                                    wa(idij)*ch(m,i-1,k,j)
    1811           0 : 540               END DO
    1812           0 : 550            END DO
    1813           0 : 560         END DO
    1814           0 : 570      END DO
    1815             : 580      RETURN
    1816             :       END SUBROUTINE vradbg
    1817             : 
    1818           0 :       SUBROUTINE vrftb1(m,n,c,ch,mdimc,wa,fac)
    1819             : 
    1820             : !     VRFFTPK, VERSION 1, AUGUST 1985
    1821             : 
    1822             :          IMPLICIT NONE
    1823             :          INTEGER, INTENT(IN) :: m, n, mdimc
    1824             :          REAL, INTENT(IN)    :: wa(n), fac(15)
    1825             :          REAL, INTENT(INOUT) :: c(mdimc,n), ch(mdimc,n)
    1826             : 
    1827             :          INTEGER :: i, j, nf, na, l1, iw, k1, ip, ipo, idl1, ix2, ix3, ix4
    1828             :          INTEGER :: ido, l2
    1829             :          REAL    :: scale
    1830             : 
    1831           0 :          nf = fac(2)
    1832           0 :          na = 0
    1833           0 :          l1 = 1
    1834           0 :          iw = 1
    1835           0 :          DO 160 k1 = 1,nf
    1836           0 :             ip = fac(k1+2)
    1837           0 :             l2 = ip*l1
    1838           0 :             ido = n/l2
    1839           0 :             idl1 = ido*l1
    1840           0 :             IF (ip /= 4) GO TO 30
    1841           0 :             ix2 = iw + ido
    1842           0 :             ix3 = ix2 + ido
    1843           0 :             IF (na /= 0) GO TO 10
    1844           0 :             CALL vradb4(m,ido,l1,c,ch,mdimc,wa(iw),wa(ix2),wa(ix3))
    1845           0 :             GO TO 20
    1846           0 : 10          CALL vradb4(m,ido,l1,ch,c,mdimc,wa(iw),wa(ix2),wa(ix3))
    1847           0 : 20          na = 1 - na
    1848           0 :             GO TO 150
    1849           0 : 30          IF (ip /= 2) GO TO 60
    1850           0 :             IF (na /= 0) GO TO 40
    1851           0 :             CALL vradb2(m,ido,l1,c,ch,mdimc,wa(iw))
    1852           0 :             GO TO 50
    1853           0 : 40          CALL vradb2(m,ido,l1,ch,c,mdimc,wa(iw))
    1854           0 : 50          na = 1 - na
    1855           0 :             GO TO 150
    1856           0 : 60          IF (ip /= 3) GO TO 90
    1857           0 :             ix2 = iw + ido
    1858           0 :             IF (na /= 0) GO TO 70
    1859           0 :             CALL vradb3(m,ido,l1,c,ch,mdimc,wa(iw),wa(ix2))
    1860           0 :             GO TO 80
    1861           0 : 70          CALL vradb3(m,ido,l1,ch,c,mdimc,wa(iw),wa(ix2))
    1862           0 : 80          na = 1 - na
    1863           0 :             GO TO 150
    1864           0 : 90          IF (ip /= 5) GO TO 120
    1865           0 :             ix2 = iw + ido
    1866           0 :             ix3 = ix2 + ido
    1867           0 :             ix4 = ix3 + ido
    1868           0 :             IF (na /= 0) GO TO 100
    1869           0 :             CALL vradb5(m,ido,l1,c,ch,mdimc,wa(iw),wa(ix2),wa(ix3),wa(ix4))
    1870           0 :             GO TO 110
    1871           0 : 100         CALL vradb5(m,ido,l1,ch,c,mdimc,wa(iw),wa(ix2),wa(ix3),wa(ix4))
    1872           0 : 110         na = 1 - na
    1873           0 :             GO TO 150
    1874           0 : 120         IF (na /= 0) GO TO 130
    1875           0 :             CALL vradbg(m,ido,ip,l1,idl1,c,c,c,ch,ch,mdimc,wa(iw))
    1876           0 :             GO TO 140
    1877           0 : 130         CALL vradbg(m,ido,ip,l1,idl1,ch,ch,ch,c,c,mdimc,wa(iw))
    1878           0 : 140         IF (ido == 1) na = 1 - na
    1879           0 : 150         l1 = l2
    1880           0 :             iw = iw + (ip-1)*ido
    1881           0 : 160      END DO
    1882           0 :          scale = sqrt(1./n)
    1883           0 :          IF (na == 0) GO TO 190
    1884           0 :          DO 180 j = 1,n
    1885           0 :             DO 170 i = 1,m
    1886           0 :                c(i,j) = scale*ch(i,j)
    1887           0 : 170         END DO
    1888           0 : 180      END DO
    1889           0 :          RETURN
    1890           0 : 190      DO 210 j = 1,n
    1891           0 :             DO 200 i = 1,m
    1892           0 :                c(i,j) = scale*c(i,j)
    1893           0 : 200         END DO
    1894           0 : 210      END DO
    1895             :          RETURN
    1896             :       END SUBROUTINE vrftb1
    1897             : 
    1898             :    END SUBROUTINE vrfftb
    1899             : 
    1900             : END MODULE m_rfft

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