ZfitGUI(varargin) fits and simulates impedance data

ZfitGUI helps to identify a right model of complex data.

Description

% The main features are:
%
% Plot.
% For each immitance types (Z, Y, C or M), the data can be plotted
% in the complex plane, as well their real, imaginary parts or
% their magnitude in function of the frequency (Log/Log).
%
% Simulation.
% The possibilities are almost infinite. Over the classical R, C,
% L electrical elements, one can use CPE (constant Phase Element)
% and even any user-defined element.
%
% Fit.
% ZfitGUI makes use of the simplex algorithm. One can put bounds to
% the parameters and vary the weight wich is defined in a matrix.
% Once a right model has been identified, the user would save time in
% using Zfit.m which is the programmatic version of ZfitGUI.
% Zfit is a shared file as well as ZfitGUI.
%
%
% This help is divided in the 6 following sections:
%
%------------- INPUTS
%------------- UIMENUS
% Plots
% Selectline
% Circuit
% Fit
% Options
% Readme
%------------- OUTPUTS
%------------- MINIMIZATION
%------------- IMMITANCES
%------------- LIMITATIONS

• MATLAB release: MATLAB 7.4 (R2007a)

[Jean-Luc Dellis]

Take notice that you may open the 'ZfitGUIdemofig' to test the working.

[Saif]

Jean-Luc

Thank you for the great submission. How do I make the LB UB work?

[Saif]

Let me elaborate more:

When I write: ZfitGUI([zr',zi',fr']), a window pops up with my nyquist plot. I then choose "SelectLine" and click on the plot. I then go to "Circuit" and I input the circuit string and the vector "Pinit" which I think it works as an initial guess. I get a fitting curve (red) by clicking on "FIT". When I go to "Options" to set "LB/UB" variables and then click "FIT" again, I get an error:

Exiting: Maximum number of function evaluations has been exceeded
         - increase MaxFunEvals option.
         Current function value: NaN

Could you please help me with that?
Thanks.

[Jean-Luc Dellis]

Hi Saif, I think all is ok except you maybe enter bad boundaries. I mean the boundaries you put do not allow the code to go toward the best parameters but to NAN. To handle that, you may simulate data. If again difficulties, please send me an email with the data, circuit, pinit and of course the LB/UB. Thanks.