Contents

• NAME
• SYNOPSIS
  • F95 INTERFACE
  • C INTERFACE
• ARGUMENTS

NAME

     zfft2i - initialize the array WSAVE, which is used  in  both
     the forward and backward transforms.

SYNOPSIS

     SUBROUTINE ZFFT2I(M, N, WORK)

     INTEGER M, N
     DOUBLE PRECISION WORK(*)

     SUBROUTINE ZFFT2I_64(M, N, WORK)

     INTEGER*8 M, N
     DOUBLE PRECISION WORK(*)

  F95 INTERFACE
     SUBROUTINE ZFFT2I(M, N, WORK)

     INTEGER :: M, N
     REAL(8), DIMENSION(:) :: WORK

     SUBROUTINE ZFFT2I_64(M, N, WORK)

     INTEGER(8) :: M, N
     REAL(8), DIMENSION(:) :: WORK

  C INTERFACE
     #include <sunperf.h>

     void zfft2i(int m, int n, double *work);

     void zfft2i_64(long m, long n, double *work);

ARGUMENTS

     M (input) Number of rows to be transformed.  M >= 0.

     N (input) Number of columns to be transformed.  N >= 0.

     WORK (input/output)
               On entry, an array of dimension (4 * (M + N) + 30)
               or  greater.   ZFFT2I needs to be called only once
               to initialize array  WORK  before  calling  ZFFT2F
               and/or  ZFFT2B  if  M, N and WORK remain unchanged
               between these calls.  Thus, subsequent  transforms
               or inverse transforms of same size can be obtained
               faster than the first since they  do  not  require
               initialization of the workspace.