vdcosqi

NAME

vdcosqi - initialize the array WSAVE, which is used in both VCOSQF and VCOSQB.

SYNOPSIS

  SUBROUTINE VDCOSQI( N, WSAVE)
  INTEGER N
  DOUBLE PRECISION WSAVE(*)
 
  SUBROUTINE VDCOSQI_64( N, WSAVE)
  INTEGER*8 N
  DOUBLE PRECISION WSAVE(*)

F95 INTERFACE

  SUBROUTINE VCOSQI( N, WSAVE)
  INTEGER :: N
  REAL(8), DIMENSION(:) :: WSAVE
 
  SUBROUTINE VCOSQI_64( N, WSAVE)
  INTEGER(8) :: N
  REAL(8), DIMENSION(:) :: WSAVE

C INTERFACE

#include <sunperf.h>

void vdcosqi(int n, double *wsave);

void vdcosqi_64(long n, double *wsave);

ARGUMENTS

* N (input): Length of the sequence to be transformed. The method is most efficient when N is a product of small primes.
* WSAVE (input): On entry, an array of dimension (2 * N + 15) or greater. VDCOSQI needs to be called only once to initialize WSAVE before calling VDCOSQF and/or VDCOSQB 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.