Contents
vrffti - initialize the array WSAVE, which is used in both
VRFFTF and VRFFTB.
SUBROUTINE VRFFTI(N, WSAVE)
INTEGER N
REAL WSAVE(*)
SUBROUTINE VRFFTI_64(N, WSAVE)
INTEGER*8 N
REAL WSAVE(*)
F95 INTERFACE
SUBROUTINE VFFTI(N, WSAVE)
INTEGER :: N
REAL, DIMENSION(:) :: WSAVE
SUBROUTINE VFFTI_64(N, WSAVE)
INTEGER(8) :: N
REAL, DIMENSION(:) :: WSAVE
C INTERFACE
#include <sunperf.h>
void vrffti(int n, float *wsave);
void vrffti_64(long n, float *wsave);
N (input) Length of the sequence to be transformed. N >= 0.
WSAVE (input)
On entry, an array of dimension (N + 15) or
greater. VRFFTI needs to be called only once to
initialize WSAVE before calling VRFFTF and/or
VRFFTB 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.