Loop analysis is a tool to let user arbitrarily draw a transfer function by varying the coefficient or component from the feedback block. On the other way, curve fitting can be done by entering points of expected gain or expected phase, by pressing "Automatic Compensation" button, the coefficient of the transfer function or components will be changed to fit those points.

Loop analysis provides the interface to customize the transfer function and shows the gain and phase of the transfer function G(s).

User can set the number of parameters by setting n., where n is the order of the transfer function. The range of a_i and b_i should be specified for curve fitting purpose. For coefficient which user may not want to be changed by our non-linear regression curve fitting engine, user simply unchecks the check box.