sconv_periodic, dconv_periodic, cconv_periodic, zconv_periodic 

Periodic concolution

FORMAT

  {S,D,C,Z}CONV_PERIODIC (x, y, out, n, status)

Arguments

  x                   real*4 | real*8 | complex*8 | complex*16
                      On entry, an array containing the data to be convolved.
                      On exit, x is unchanged.

  y                   real*4 | real*8 | complex*8 | complex*16
                      On entry, an array containing the convolution or
                      "filter" function which is to be convolved with the
                      data from the X array.
                      On exit, y is unchanged.

  out                 real*4 | real*8 | complex*8 | complex*16
                      On entry, a one-dimensional array OUT of length n.
                      On exit, out is overwritten and contains the convolved
                      data.

  n                   integer*4
                      On entry, the length of the input arrays X and Y and
                      the length of the output array OUT; n > 0.
                      On exit, n is unchanged.

  status              integer*4

                      status = 0 :DXML_SUCCESS()

                      status = 8 :DXML_ILL_N_RANGE()

Description

  The _CONV_PERIODIC functions compute the periodic convolution of two arrays
  using a discrete summing technique.

Example

  INCLUDE 'CXMLDEF.FOR'
  INTEGER*4 N, STATUS
  REAL*8 A(15000), B(15000), C(15000)
  N = 15000
  CALL DCONV_PERIODIC(A,B,C,N,STATUS)

  This FORTRAN code computes the periodic convolution of two vectors of
  double-precision real numbers, a and b, with lengths of 15000. The result
  is stored in c with length of 15000.