Function File: L = ismaxphase (b, a)
Function File: L = ismaxphase (sos)
Function File: L = ismaxphase (…, tol)

Determine whether a digital filter is maximum phase (maximum energy-delay). The filter might be defined by the numerator coefficients, b, and the denominator coefficients, a, or, alternatively, by a matrix of second-order sections, sos. A tolerance tol might be given to define when two numbers are close enough to be considered equal.

Example:

b = [1 2 4 4 2 1];
zplane (b);
ismaxphase (b)

Ref [1] Oppenheim, Alan, and Ronald Schafer. Discrete-Time Signal Processing. 3rd edition, Pearson, 2009.

Demonstration 1

The following code

 [b, a] = butter (1, .5);
 f = ismaxphase (b, a)

Produces the following output

f = 0

Package: signal