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