dcosqb
dcosqb - synthesize a Fourier sequence from its representation 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(*)
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
#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.