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

NAME

vdcosqb - synthesize a Fourier sequence from its representation in terms of a cosine series with odd wave numbers. The VCOSQ operations are normalized, so a call of VCOSQF followed by a call of VCOSQB will return the original sequence.

SYNOPSIS

  SUBROUTINE VDCOSQB( M, N, X, XT, MDIMX, WSAVE)
  INTEGER M, N, MDIMX
  DOUBLE PRECISION X(MDIMX,*), XT(MDIMX,*), WSAVE(*)

  SUBROUTINE VDCOSQB_64( M, N, X, XT, MDIMX, WSAVE)
  INTEGER*8 M, N, MDIMX
  DOUBLE PRECISION X(MDIMX,*), XT(MDIMX,*), WSAVE(*)

F95 INTERFACE

  SUBROUTINE COSQB( [M], [N], X, XT, [MDIMX], WSAVE)
  INTEGER :: M, N, MDIMX
  REAL(8), DIMENSION(:) :: WSAVE
  REAL(8), DIMENSION(:,:) :: X, XT

  SUBROUTINE COSQB_64( [M], [N], X, XT, [MDIMX], WSAVE)
  INTEGER(8) :: M, N, MDIMX
  REAL(8), DIMENSION(:) :: WSAVE
  REAL(8), DIMENSION(:,:) :: X, XT

C INTERFACE

#include <sunperf.h>

void vdcosqb(int m, int n, double *x, double *xt, int mdimx, double *wsave);

void vdcosqb_64(long m, long n, double *x, double *xt, long mdimx, double *wsave);

ARGUMENTS

• M (input)
  The number of sequences to be transformed. M > = 0.

• 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, the rows contain the sequences to be transformed. On exit, the quarter-wave cosine synthesis of the input.

• XT (input)
  A work array.

• MDIMX (input)
  Leading dimension of the arrays X and XT as specified in a dimension or type statement. MDIMX > = M.

• WSAVE (input)
  On entry, an array of dimension (2 * N + 15) or greater initialized by VCOSQI.