NAME

zfft3i - initialize the array WSAVE, which is used in both ZFFT3F and ZFFT3B.

SYNOPSIS

  SUBROUTINE ZFFT3I( M, N, K, WORK)
  INTEGER M, N, K
  DOUBLE PRECISION WORK(*)

  SUBROUTINE ZFFT3I_64( M, N, K, WORK)
  INTEGER*8 M, N, K
  DOUBLE PRECISION WORK(*)

  SUBROUTINE ZFFT3I( M, N, K, WORK)
  INTEGER :: M, N, K
  REAL(8), DIMENSION(:) :: WORK

  SUBROUTINE ZFFT3I_64( M, N, K, WORK)
  INTEGER(8) :: M, N, K
  REAL(8), DIMENSION(:) :: WORK

#include <sunperf.h>

void zfft3i(int m, int n, int k, double *work);

void zfft3i_64(long m, long n, long k, double *work);

M (input)
Number of rows to be transformed. M > = 0.
N (input)
Number of columns to be transformed. N > = 0.
K (input)
Number of planes to be transformed. K > = 0.
WORK (input/output)
On entry, an array of dimension (4*(M + N + K) + 45) or greater. ZFFT3I needs to be called only once to initialize array WORK before calling ZFFT3F and/or ZFFT3B if M, N, K 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.