zfft2i(3P) Sun Performance Library zfft2i(3P)NAMEzfft2i - 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 initializa‐
tion of the workspace.
6 Mar 2009 zfft2i(3P)
