Name

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

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

nx_strideinteger∗4
Distance between elements in the X array; nx_stride > 0

yreal∗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_strideinteger∗4
Distance between elements in the Y array; ny_stride > 0

outreal∗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_strideinteger∗4
Specifies the distance between elements in the OUT array; out_stride > 0

nx, nyinteger∗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_flaglogical∗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_flaglogical∗4
Defines the operation of the convolution to scale the output.

TRUE: Scale the output. 

FALSE: Do not scale. 

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

scale_strideinteger∗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

0DXML_SUCCESS()

8DXML_ILL_N_RANGE()

13DXML_BAD_STRIDE()

Example

  INCLUDE ’{file_location}DXMLDEF.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.