Contents
dezftb - computes a periodic sequence from its Fourier coef-
ficients. DEZFTB is a simplified but slower version of
DFFTB.
SUBROUTINE DEZFTB(N, R, AZERO, A, B, WSAVE)
INTEGER N
DOUBLE PRECISION AZERO
DOUBLE PRECISION R(*), A(*), B(*), WSAVE(*)
SUBROUTINE DEZFTB_64(N, R, AZERO, A, B, WSAVE)
INTEGER*8 N
DOUBLE PRECISION AZERO
DOUBLE PRECISION R(*), A(*), B(*), WSAVE(*)
F95 INTERFACE
SUBROUTINE DEZFTB(N, R, AZERO, A, B, WSAVE)
INTEGER :: N
REAL(8) :: AZERO
REAL(8), DIMENSION(:) :: R, A, B, WSAVE
SUBROUTINE DEZFTB_64(N, R, AZERO, A, B, WSAVE)
INTEGER(8) :: N
REAL(8) :: AZERO
REAL(8), DIMENSION(:) :: R, A, B, WSAVE
C INTERFACE
#include <sunperf.h>
void dezftb(int n, double *r, double azero, double *a, dou-
ble *b, double *wsave);
void dezftb_64(long n, double *r, double azero, double *a,
double *b, double *wsave);
N (input) Length of the sequence to be synthesized. The
method is most efficient when N is the product of
small primes. N >= 0.
R (output)
On exit, the Fourier synthesis of the inputs.
AZERO (input)
On entry, the constant Fourier coefficient A0.
Unchanged on exit.
A (input/output)
On entry, array that contains the remaining
Fourier coefficients. On exit, these arrays are
unchanged.
B (input/output)
On entry, array that contains the remaining
Fourier coefficients. On exit, these arrays are
unchanged.
WSAVE (input)
On entry, an array with dimension of at least (3 *
N + 15), initialized by DEZFTI.