Contents

• NAME
• SYNOPSIS
  • F95 INTERFACE
  • C INTERFACE
• ARGUMENTS

NAME

     dezftb - computes a periodic sequence from its Fourier coef-
     ficients.   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,  dou-
               ble *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.