— Function File: convmtx (a, n)

If a is a column vector and x is a column vector of length n, then

convmtx(a, n) * x

gives the convolution of of a and x and is the same as conv(a, x). The difference is if many vectors are to be convolved with the same vector, then this technique is possibly faster.

Similarly, if a is a row vector and x is a row vector of length n, then

x * convmtx(a, n)

is the same as conv(x, a).