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Updated: June 2017
 
 

rfftb (3p)

Name

rfftb - compute a periodic sequence from its Fourier coefficients. The RFFT operations are unnormalized, so a call of RFFTF followed by a call of RFFTB will multiply the input sequence by N.

Synopsis

SUBROUTINE RFFTB(N, X, WSAVE)

INTEGER N
REAL X(*), WSAVE(*)

SUBROUTINE RFFTB_64(N, X, WSAVE)

INTEGER*8 N
REAL X(*), WSAVE(*)




F95 INTERFACE
SUBROUTINE FFTB(N, X, WSAVE)

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

SUBROUTINE FFTB_64(N, X, WSAVE)

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




C INTERFACE
#include <sunperf.h>

void rfftb(int n, float *x, float *wsave);

void rfftb_64(long n, float *x, float *wsave);

Description

Oracle Solaris Studio Performance Library                            rfftb(3P)



NAME
       rfftb - compute a periodic sequence from its Fourier coefficients.  The
       RFFT operations are unnormalized, so a call of RFFTF followed by a call
       of RFFTB will multiply the input sequence by N.


SYNOPSIS
       SUBROUTINE RFFTB(N, X, WSAVE)

       INTEGER N
       REAL X(*), WSAVE(*)

       SUBROUTINE RFFTB_64(N, X, WSAVE)

       INTEGER*8 N
       REAL X(*), WSAVE(*)




   F95 INTERFACE
       SUBROUTINE FFTB(N, X, WSAVE)

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

       SUBROUTINE FFTB_64(N, X, WSAVE)

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




   C INTERFACE
       #include <sunperf.h>

       void rfftb(int n, float *x, float *wsave);

       void rfftb_64(long n, float *x, float *wsave);



ARGUMENTS
       N (input) Length  of the sequence to be transformed.  These subroutines
                 are most efficient when N is a product of small primes.  N >=
                 0.


       X (input/output)
                 On  entry, an array of length N containing the sequence to be
                 transformed.


       WSAVE (input/output)
                 On entry, WSAVE must be an array of dimension (2 * N + 15) or
                 greater and must have been initialized by RFFTI.




                                  7 Nov 2015                         rfftb(3P)