• NAME
• SYNOPSIS
• F95 INTERFACE
• C INTERFACE
• ARGUMENTS

NAME

cffti - initialize the array WSAVE, which is used in both CFFTF and CFFTB.

SYNOPSIS

  SUBROUTINE CFFTI( N, WSAVE)
  INTEGER N
  REAL WSAVE(*)

  SUBROUTINE CFFTI_64( N, WSAVE)
  INTEGER*8 N
  REAL WSAVE(*)

F95 INTERFACE

  SUBROUTINE CFFTI( N, WSAVE)
  INTEGER :: N
  REAL, DIMENSION(:) :: WSAVE

  SUBROUTINE CFFTI_64( N, WSAVE)
  INTEGER(8) :: N
  REAL, DIMENSION(:) :: WSAVE

C INTERFACE

#include <sunperf.h>

void cffti(int n, float *wsave);

void cffti_64(long n, float *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. CFFTI needs to be called only once to initialize array WORK before calling CFFTF and/or CFFTB 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.