zffti(3P) Sun Performance Library zffti(3P)NAMEzffti - initialize the array WSAVE, which is used in both ZFFTF and
ZFFTB.
SYNOPSIS
SUBROUTINE ZFFTI(N, WSAVE)
INTEGER N
DOUBLE PRECISION WSAVE(*)
SUBROUTINE ZFFTI_64(N, WSAVE)
INTEGER*8 N
DOUBLE PRECISION WSAVE(*)
F95 INTERFACE
SUBROUTINE ZFFTI(N, WSAVE)
INTEGER :: N
REAL(8), DIMENSION(:) :: WSAVE
SUBROUTINE ZFFTI_64(N, WSAVE)
INTEGER(8) :: N
REAL(8), DIMENSION(:) :: WSAVE
C INTERFACE
#include <sunperf.h>
void zffti(int n, double *wsave);
void zffti_64(long n, double *wsave);
ARGUMENTS
N (input) Length of the sequence to be transformed. N >= 0.
WSAVE (input/output)
On entry, an array of dimension (4 * N + 15) or greater.
ZFFTI needs to be called only once to initialize array WORK
before calling ZFFTF and/or ZFFTB if N and WSAVE 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.
6 Mar 2009 zffti(3P)