sconv_nonperiodic_ext, dconv_nonperiodic_ext, cconv_nonperiodic_ext, zconv_nonperiodic_ext 

Extended nonperiodic convolution

FORMAT

  status = {S,D,C,Z}CONV_NONPERIODIC_EXT

  (x, nx_stride, y, ny_stride,  out, out_stride, nx, ny, n_out_start,
  n_out_end, add_flag, scale_flag,  scale, scale_stride)

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.

  nx_stride           integer*4
                      Distance between elements in the X array; nx_stride > 0

  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.

  ny_stride           integer*4
                      Distance between elements in the Y array; ny_stride > 0

  out                 real*4 | real*8 | complex*8 | complex*16
                      On entry, a one-dimensional array OUT of length nx + ny
                      - 1.
                      On exit, out contains the convolution coefficients.

  out_stride          integer*4
                      Specifies the distance between elements in the OUT
                      array; out_stride > 0

  nx, ny              integer*4
                      Specifies the number of values to be operated on; nx,
                      ny > 0

  n_out_start, n_out_end
                      integer*4
                      Specifies the range of coefficients computed; n_out_end
                      > n_out_start. The OUT array has zero values for
                      indices less than 0 or greater than
                       nx + ny -2.

                      For example, in the case of nx = 50 and ny = 100, the
                      range of locations is 0 through 148. If you specify
                      n_out_start = 5 and n_out_end = 10, the convolution
                      function generates numbers for OUT(5) through OUT(10)
                      and puts the results in location 0 through 5 of the OUT
                      array.

                      You can also specify a range that is larger than the
                      array, creating null elements in the output array. For
                      example, using the same input array, you can specify
                      n_out_start = -10 and n_out_end = 200. The convolution
                      function can generate values for 0 through 148, putting
                      them in location 10 through 158 of the output array. It
                      puts null elements in the locations between 0 and 9 and
                      between 159 and 200.

  add_flag            logical*4
                      Defines the operation of the convolution to add output
                      to an existing OUT array, without overwriting it.

                      TRUE: Add the result of the operation to OUT array.

                      FALSE: Overwrite the existing OUT array.

  scale_flag          logical*4
                      Defines the operation of the convolution to scale the
                      output.

     TRUE: Scale the output.

     FALSE: Do not scale.

  scale               real*4 | real*8 | complex*8 | complex*16
                      The value used to scale the output. The type of value
                      depends on scale_stride.

  scale_stride        integer*4
                      Defines how the scale operation is performed.
                      scale_stride# 0:

      = 0 : Scale by a scalar value

      > 0: Scale by a vector, used as the stride of scale

Description

  The _CONV_NONPERIODIC_EXT functions compute the nonperiodic convolution
  with options to control the result.

Return Values

  0                  DXML_SUCCESS()

  8                  DXML_ILL_N_RANGE()

  13                 DXML_BAD_STRIDE()

Example

    INCLUDE 'CXMLDEF.FOR'
    INTEGER*4 N,STATUS
    REAL*8 A(50),B(100),C(6),SCALE_VALUE
    SCALE_VALUE = 2.0
    STATUS = DCONV_NONPERIODIC_EXT(A,1,B,1,C,1,50,100,5,10,.FALSE.,.TRUE.,
  * SCALE_VALUE,0)

  This FORTRAN code computes six values of a nonperiodic convolution of two
  vectors, C(5) to C(10), of double-precision real numbers, a and b, with
  lengths of 50 and 100, respectively. The result is scaled by 2.0 and stored
  in c with length of 6.