MATLAB: How is sensitivity output of wcgain and robstab functions determined

Robust Control Toolbox

I am trying to understand how sensitivity is calculated from these functions. I have gone through the documentation but would like additional details on the calculations.

Best Answer

The sensitivity is determined via a finite difference approximation. For each block, the algorithm will perturb the amount of uncertainty by the fraction specified in wcgainOptions, recompute the mu upper bound, and take the ratio of variations.
For additional information, please see the source code rctutil.getCSensitivity for details. You can access this in MATLAB using the following:
>> edit rctutil.getCSensitivity
It might be beneficial if you set breakpoints while running your scripts to see how the individual components are computed while determining sensitivity.