Contents

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

NAME

     rffti - initialize the array WSAVE, which is  used  in  both
     RFFTF and RFFTB.

SYNOPSIS

     SUBROUTINE RFFTI(N, WSAVE)

     INTEGER N
     REAL WSAVE(*)

     SUBROUTINE RFFTI_64(N, WSAVE)

     INTEGER*8 N
     REAL WSAVE(*)

  F95 INTERFACE
     SUBROUTINE FFTI(N, WSAVE)

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

     SUBROUTINE FFTI_64(N, WSAVE)

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

  C INTERFACE
     #include <sunperf.h>

     void rffti(int n, float *wsave);

     void rffti_64(long n, float *wsave);

ARGUMENTS

     N (input) Length of the sequence to be transformed.  N >= 0.

     WSAVE (input)
               On entry, an array of dimension (2 * N  +  15)  or
               greater.   RFFTI  needs  to be called only once to
               initialize array WORK before calling RFFTF  and/or
               RFFTB  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.