Contents
dcosqf - compute the Fourier coefficients in a cosine series
representation with only odd wave numbers. The COSQ opera-
tions 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 DCOSQF(N, X, WSAVE)
INTEGER N
DOUBLE PRECISION X(*), WSAVE(*)
SUBROUTINE DCOSQF_64(N, X, WSAVE)
INTEGER*8 N
DOUBLE PRECISION X(*), WSAVE(*)
F95 INTERFACE
SUBROUTINE COSQF([N], X, WSAVE)
INTEGER :: N
REAL(8), DIMENSION(:) :: X, WSAVE
SUBROUTINE COSQF_64([N], X, WSAVE)
INTEGER(8) :: N
REAL(8), DIMENSION(:) :: X, WSAVE
C INTERFACE
#include <sunperf.h>
void dcosqf(int n, double *x, double *wsave);
void dcosqf_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 transform of the input.
WSAVE (input)
On entry, an array with dimension of at least (3
* N + 15) that has been initialized by DCOSQI.