User`s guide

Performance
3-21
Performance
conv2 function performance improvements with three inputs
The performance of the conv2 function improves when using the conv2(h1,h2,A)
syntax.
filter function performance improvements for FIR and IIR
The performance of the filter function, filter(b,a,X), improves in the following cases:
• where a is a scalar and X is a sufficiently long vector (FIR filter)
• where a is a vector and X is a vector, matrix, or multidimensional array (IIR filter)