Contents
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.
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);
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.