HP MLIB User's Guide Vol. 2 7th Ed.

Chapter 6 Correlation and Convolution Subprograms 601

Tapered correlation and convolution STCONV/DTCONV

Input x Array containing the operand (or trace) vector x of

length n. lenx = (n−1)×|incx|+1.

incx Increment for the array x, incx ≠ 0. x

is stored in

x((i−1)×incx+1). incx is normally positive whether

computing the correlation or the convolution. Use

incx = 1 if the vector x is stored contiguously in array x,

that is, if x

is stored in x(i). Refer to “Notes.”

w Array containing the operator (or kernel) vector w of

length n. lenw = (n−1)×|incw|+1. Refer to the

description of incw for alternate usage of w.

incw Increment for the array w, incw ≠ 0. w

is stored in

w((j−1)×incw+1). incw is normally positive to compute

the correlation and negative to compute the

convolution.

Use incw = 1 if computing the correlation and vector w

is stored contiguously in forward order in array w, that

is, if w

is stored in w(j). Refer to “Example 1” on

page 602. Also, use incw = 1 if computing the

convolution and vector w is stored contiguously in

backward order in array w, that is, if w

is stored in

w(n+1−j).

Use incw = −1 if computing the convolution and vector

w is stored contiguously in forward order in array w,

that is, if w

is stored in w(j). In this case, in order to

index backward through the w array, the w argument

is usually coded as w(n). Refer to “Notes” on page 602

and “Example 2” on page 602.

incy Increment for the array y, incy ≠ 0. is stored in

y((k−1)×incy+1). incy will normally be positive whether

computing the correlation or the convolution. Use incy

= 1 if the vector y is stored contiguously in array y, that

is, if is stored in y(k). Refer to “Notes.”

m The length of the y vector. m > 0.

n The length of the x and w vector. n > 0.