Contents
ezfftf - computes the Fourier coefficients of a periodic
sequence. EZFFTF is a simplified but slower version of
RFFTF.
SUBROUTINE EZFFTF(N, R, AZERO, A, B, WSAVE)
INTEGER N
REAL AZERO
REAL R(*), A(*), B(*), WSAVE(*)
SUBROUTINE EZFFTF_64(N, R, AZERO, A, B, WSAVE)
INTEGER*8 N
REAL AZERO
REAL R(*), A(*), B(*), WSAVE(*)
F95 INTERFACE
SUBROUTINE EZFFTF(N, R, AZERO, A, B, WSAVE)
INTEGER :: N
REAL :: AZERO
REAL, DIMENSION(:) :: R, A, B, WSAVE
SUBROUTINE EZFFTF_64(N, R, AZERO, A, B, WSAVE)
INTEGER(8) :: N
REAL :: AZERO
REAL, DIMENSION(:) :: R, A, B, WSAVE
C INTERFACE
#include <sunperf.h>
void ezfftf(int n, float *r, float azero, float *a, float
*b, float *wsave);
void ezfftf_64(long n, float *r, float azero, float *a,
float *b, float *wsave);
N (input) Length of the sequence to be transformed. The
method is most efficient when N is the product of
small primes. N >= 0.
R (input) A real array of length N containing the sequence
to be transformed. On exit, R is unchanged.
AZERO (output)
On exit, the sum from i=1 to i=n of r(i)/n.
A (input/output)
On entry, arrays that contain the remaining
Fourier coefficients. On exit, these arrays are
unchanged.
B (input/output)
On entry, arrays that contain 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 EZFFTI.