NAME

cfft2i - initialize the array WSAVE, which is used in both the forward and backward transforms.

SYNOPSIS

  SUBROUTINE CFFT2I( M, N, WORK)
  INTEGER M, N
  REAL WORK(*)

  SUBROUTINE CFFT2I_64( M, N, WORK)
  INTEGER*8 M, N
  REAL WORK(*)

  SUBROUTINE CFFT2I( M, N, WORK)
  INTEGER :: M, N
  REAL, DIMENSION(:) :: WORK

  SUBROUTINE CFFT2I_64( M, N, WORK)
  INTEGER(8) :: M, N
  REAL, DIMENSION(:) :: WORK

#include <sunperf.h>

void cfft2i(int m, int n, float *work);

void cfft2i_64(long m, long n, float *work);

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. CFFT2I needs to be called only once to initialize array WORK before calling CFFT2F and/or CFFT2B 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.