Contents

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

NAME

     dcosqb - synthesize a Fourier sequence from its  representa-
     tion in terms of a cosine series with odd wave numbers.  The
     COSQ operations are unnormalized inverses of themselves,  so
     a  call  to  COSQF followed by a call to COSQB will multiply
     the input sequence by 4 * N.

SYNOPSIS

     SUBROUTINE DCOSQB(N, X, WSAVE)

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

     SUBROUTINE DCOSQB_64(N, X, WSAVE)

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

  F95 INTERFACE
     SUBROUTINE COSQB([N], X, WSAVE)

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

     SUBROUTINE COSQB_64([N], X, WSAVE)

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

  C INTERFACE
     #include <sunperf.h>

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

     void dcosqb_64(long n, double *x, double *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.   On  exit,  the
               quarter-wave cosine synthesis of the input.
     WSAVE (input)
               On entry, an array with dimension of at least (3 *
               N + 15) that has been initialized by DCOSQI.