Function File: L = filternorm (b, a)
Function File: L = filternorm (b, a, pnorm)
Function File: L = filternorm (b, a, 2, tol)

Compute the 2-norm of a digital filter defined by the numerator coefficients, b, and the denominator coefficients, a. It is also possible to compute the infinity-norm by passing inf in the pnorm parameter. pnorm only accepts 2 or inf.

Example: 

[b, a] = butter (8, 0.5);
filternorm (b, a)

Demonstration 1

The following code

 b = [1 0];
 a = [1 1];
 L = filternorm (b, a)

Produces the following output

L = 5.6569

Demonstration 2

The following code

 [b, a] = butter(5, .5);
 L = filternorm (b, a)
 ## test input validation

Produces the following output

L = 0.7071

Package: signal