dezftb

NAME

dezftb - computes a periodic sequence from its Fourier coefficients. DEZFTB is a simplified but slower version of DFFTB.

SYNOPSIS 

  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, double *b, double *wsave);

void dezftb_64(long n, double *r, double azero, double *a, double *b, double *wsave);

ARGUMENTS

* 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.