dcost (3p)

Name

dcost - compute the discrete Fourier cosine transform of an even sequence. The COST transforms are unnormalized inverses of themselves, so a call of COST followed by another call of COST will multiply the input sequence by 2 * (N-1).

Synopsis

SUBROUTINE DCOST(N, X, WSAVE)

INTEGER N
DOUBLE PRECISION X(*), WSAVE(*)

SUBROUTINE DCOST_64(N, X, WSAVE)

INTEGER*8 N
DOUBLE PRECISION X(*), WSAVE(*)




F95 INTERFACE
SUBROUTINE COST(N, X, WSAVE)

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

SUBROUTINE COST_64(N, X, WSAVE)

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




C INTERFACE
#include <sunperf.h>

void dcost(int n, double *x, double *wsave);

void dcost_64(long n, double *x, double *wsave);

Description

Oracle Solaris Studio Performance Library                            dcost(3P)



NAME
       dcost  -  compute  the  discrete  Fourier  cosine  transform of an even
       sequence.  The COST transforms are unnormalized inverses of themselves,
       so  a  call  of COST followed by another call of COST will multiply the
       input sequence by 2 * (N-1).


SYNOPSIS
       SUBROUTINE DCOST(N, X, WSAVE)

       INTEGER N
       DOUBLE PRECISION X(*), WSAVE(*)

       SUBROUTINE DCOST_64(N, X, WSAVE)

       INTEGER*8 N
       DOUBLE PRECISION X(*), WSAVE(*)




   F95 INTERFACE
       SUBROUTINE COST(N, X, WSAVE)

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

       SUBROUTINE COST_64(N, X, WSAVE)

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




   C INTERFACE
       #include <sunperf.h>

       void dcost(int n, double *x, double *wsave);

       void dcost_64(long n, double *x, double *wsave);



ARGUMENTS
       N (input) Length of the sequence to be transformed.  These  subroutines
                 are  most  efficient when N - 1 is a product of small primes.
                 N >= 2.


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


       WSAVE (input)
                 On  entry, an array with dimension of at least  (3 * N + 15),
                 initialized by DCOSTI.




                                  7 Nov 2015                         dcost(3P)