Contents
vzffti - initialize the array WSAVE, which is used in both
VZFFTF and VZFFTB.
SUBROUTINE VZFFTI(N, WSAVE)
DOUBLE COMPLEX WSAVE(*)
INTEGER N
SUBROUTINE VZFFTI_64(N, WSAVE)
DOUBLE COMPLEX WSAVE(*)
INTEGER*8 N
F95 INTERFACE
SUBROUTINE VFFTI(N, WSAVE)
COMPLEX(8), DIMENSION(:) :: WSAVE
INTEGER :: N
SUBROUTINE VFFTI_64(N, WSAVE)
COMPLEX(8), DIMENSION(:) :: WSAVE
INTEGER(8) :: N
C INTERFACE
#include <sunperf.h>
void vzffti(int n, doublecomplex *wsave);
void vzffti_64(long n, doublecomplex *wsave);
N (input) Length of the sequence to be transformed. N >= 0.
WSAVE (input)
On entry, an array of dimension (N + 15) or
greater. VZFFTI needs to be called only once to
initialize WSAVE before calling VZFFTF and/or
VZFFTB 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.