Automatic Creation of Uncertainity Weighting Filter

Uncertainity representation on robust control is very important issue. System uncertainity is presenting with frequency response (such as bode or sigma) and we are creating a transfer function that will cover this uncertainity with upper bound.

My question is can we generate auotamatically a transfer function (weighting filter) of an uncertainity of its upper bound over frequency response?

I mean I need a code that will select upper limits of frequency response of uncertainity and it will create a transfer function which covers this uncertainity