How do I use ga correctly? fitness function

Hello together,

I am an student at the University of Ilmenau and i am also working there.

I got a big Matlab file which does not working and my task is to fix it. I know where the problem ist but I have never used the fitness function in matlab before. Another problem is that i do not know what the inputs of the function are.

The Programm does not work for its own it is only a function for another bigger programm but maybe someone solve the problem with the ga function

Here is the hole code and in line 88 (underlined) is the fitness function:

function [rUI, oMdl, vMdl] = guiDNLRX(f)

    handles = guihandles(f);
    layout_fcn(handles.panel_ident);
    setCallbacks(f);
    setDefaults(f);
    
    rUI  = @readUserInput;
    oMdl = @optModel;
    vMdl = @validModel;
    
end

function setCallbacks(f) 


end

function setDefaults(f)
    handles = guihandles(f);
    
    try
        load('defaultsDNLRX.mat');
        set(handles.DNLRX_M,'string',defaults(1));
        set(handles.DNLRX_n,'string',defaults(2));
        set(handles.DNLRX_nx,'string',defaults(3));
        set(handles.DNLRX_minD,'string',defaults(4));
        set(handles.DNLRX_maxD,'string',defaults(5));
        set(handles.DNLRX_alpha,'string',defaults(6));  
    catch
        set(handles.DNLRX_M,'string',5);
        set(handles.DNLRX_n,'string',0);
        set(handles.DNLRX_nx,'string',7);
        set(handles.DNLRX_minD,'string',0);
        set(handles.DNLRX_maxD,'string',3e-6);
        set(handles.DNLRX_alpha,'string',20);    
    end
end

function [options, errorflag, errorstr] = readUserInput(f,options,errorflag,errorstr)
    
    handles = guihandles(f);
    options.M  = str2double(get(handles.DNLRX_M,'String'));
    options.n  = str2double(get(handles.DNLRX_n,'String'));
    options.nx = str2double(get(handles.DNLRX_nx,'String'));
    options.bounds(1) = str2double(get(handles.DNLRX_minD,'String'));
    options.bounds(2) = str2double(get(handles.DNLRX_maxD,'String'));
    
    options.alpha     = str2double(get(handles.DNLRX_alpha,'String'));
    
    defaults = [options.M options.n options.nx options.bounds options.alpha];
    save('defaultsDNLRX','defaults');
    
    if ((options.n<0)||(options.nx<0)||(options.M<=0))
        errorflag = 1;
        errorstr = 'Invalid model order';    
    end
    if ((options.bounds(2)<=0)||(options.bounds(1)<0)||(options.alpha<=0))
        errorflag=1;
        errorstr='Invalid ident.parameter';
    end
end

function [result] = optModel(data, opts)
    % run Identification method
    
    addpath models
    model = @DNLRX;
    linOptFcn = @optLinModel;
    
    %addpath linOptFcns
    %linOptFcn = @optLinDnlrx;
    
    tic
    warning off Matlab:rankDeficientMatrix
    
    bounds=zeros(opts.M,2);
    bounds(:,1) = opts.bounds(1);
    bounds(:,2) = opts.bounds(2);
       
    IdentParams             = opts;
    IdentParams.input       = data.x(1:opts.downsampling:end); %position
    IdentParams.output      = data.u(1:opts.downsampling:end); %force
    IdentParams.alpha       = ceil(opts.alpha/opts.downsampling);
    IdentParams.modelFcn    = model;
    
    % call the GA
    [d endPop trace]=ga([],bounds(:,1),bounds(:,2),linOptFcn,IdentParams,[70 -1],'maxGenTerm',opts.numGen);

    clear endPop

    %%Simplex (Nelder-Mead) optimization
    simplexOptions = optimset('Display','Iter','MaxIter',opts.iterSimplex,'TolFun',10^(-5));
    d = fminsearch(@(d) feval(linOptFcn,d,IdentParams,bounds(:,1),bounds(:,2)),d,simplexOptions);

    warning on Matlab:rankDeficientMatrix
    
    % für filterparameter jeden verfügbaren Wert benutzten
    IdentParams.input   = data.x; %position
    IdentParams.output  = data.u; %force   
    IdentParams.alpha   = opts.alpha;
    
    result = opts;
    
    %für Berechnung der Filterparameter und Darstellung der Ergebnisse
	[~,result.d,Theta,u_model,IdentParams]=feval(linOptFcn,d,IdentParams);
    
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

    result.NRMSE = calcNRMSE(IdentParams.output,u_model);
    
    if (opts.offset~=0)
        result.offset=Theta(end);
        Theta=Theta(1:end-1);
    else
        result.offset = 0;
    end
    
    result.g = Theta(1:opts.nx+1); %coefficiets input FIR filter
    result.theta = Theta(opts.nx+2:end); %coefficients spring deformation FIR filter
    
    idx=length(data.u)-length(u_model)+1;
    result.u        = data.u(idx:end);
    result.x        = data.x(idx:end);
    result.u_model  = u_model;

    result.identDuration=toc;
    
    %Anzeige result Struktur
    result
    
    disp(['Elapsed time is ' num2str(result.identDuration) ' seconds.']);

    title = ['DNLRX(' num2str(result.M) ',' num2str(result.n) ',' num2str(result.nx) ') model' ];
    plotResult(result,'Trainingsdatensatz',title);
    
end

function [result] = validModel(data, opts)
    addpath models
    result = [];
    u_model=DNLRX(data.x,opts);
    if isfield(data,'u')
        %Validierung mit Messdaten
        result = opts;
        idx=length(data.x)-length(u_model)+1;
        result.u_model = u_model;
        result.x = data.x(idx:end);
        result.u = data.u(idx:end);
        result.NRMSE = calcNRMSE(data.u,u_model);
        titleName = ['DNLRX(' num2str(result.M) ',' num2str(result.n) ',' num2str(result.nx) ') model' ];
        plotResult(result,'Validierungsdatensatz',titleName)
    else
        %optische Validierung mit Sinusfunktion
        figure
        plot(u_model)
        grid
    end
end

function layout_fcn(h25)
    h26 = uicontrol(...
    'Parent',h25,...
    'BackgroundColor',[1 1 1],...
    'Position',[52 90 30 20],...
    'String','',...
    'Style','edit',...
    'Tag','DNLRX_M');

    h27 = uicontrol(...
    'Parent',h25,...
    'BackgroundColor',[1 1 1],...
    'Position',[52 65 30 20],...
    'String','',...
    'Style','edit',...
    'Tag','DNLRX_n');

    h28 = uicontrol(...
    'Parent',h25,...
    'BackgroundColor',[1 1 1],...
    'Position',[52 40 30 20],...
    'String','',...
    'Style','edit',...
    'Tag','DNLRX_nx');

    h29 = uicontrol(...
    'Parent',h25,...
    'FontSize',10,...
    'HorizontalAlignment','left',...
    'Position',[25 89 20 20],...
    'String','M',...
    'Style','text',...
    'Tag','DNLRX_MText');

    h31 = uicontrol(...
    'Parent',h25,...
    'FontSize',10,...
    'HorizontalAlignment','left',...
    'Position',[25 64 20 20],...
    'String','n',...
    'Style','text',...
    'Tag','DNLRX_nText');

    h30 = uicontrol(...
    'Parent',h25,...
    'FontSize',10,...
    'HorizontalAlignment','left',...
    'Position',[25 40 20 20],...
    'String','nx',...
    'Style','text',...
    'Tag','DNLRX_nxText');

    %Min Schwellwerte
    h38 = uicontrol(...
    'Parent',h25,...
    'Units','pixels',...
    'FontSize',10,...
    'HorizontalAlignment','left',...
    'Position',[220 89 122 20],...
    'String','Min Schwellwerte',...
    'Style','text',...
    'Tag','DNLRX_minD_text');
    h39 = uicontrol(...
    'Parent',h25,...
    'BackgroundColor',[1 1 1],...
    'Position',[350 90 50 20],...
    'String','',...
    'Style','edit',...
    'Tag','DNLRX_minD');

    %Max Schwellwerte
    h38 = uicontrol(...
    'Parent',h25,...
    'Units','pixels',...
    'FontSize',10,...
    'HorizontalAlignment','left',...
    'Position',[220 64 122 20],...
    'String','Max Schwellwerte',...
    'Style','text',...
    'Tag','DNLRX_maxD_text');
    h39 = uicontrol(...
    'Parent',h25,...
    'BackgroundColor',[1 1 1],...
    'Position',[350 65 50 20],...
    'String','',...
    'Style','edit',...
    'Tag','DNLRX_maxD');

    %alpha
    h38 = uicontrol(...
    'Parent',h25,...
    'Units','pixels',...
    'FontSize',10,...
    'HorizontalAlignment','left',...
    'Position',[220 39 122 20],...
    'String','alpha',...
    'Style','text',...
    'Tag','DNLRX_alpha_text');
    h39 = uicontrol(...
    'Parent',h25,...
    'BackgroundColor',[1 1 1],...
    'Position',[350 40 50 20],...
    'String','',...
    'Style','edit',...
    'Tag','DNLRX_alpha');
end

This is the error message

>> frictionGUI

Error using ga (line 310)

Fitness function must be a function handle.

Error in guiDNLRX>optModel (line 88)

[d endPop trace]=ga([],bounds(:,1),bounds(:,2),linOptFcn,IdentParams,[70 -1],'maxGenTerm',opts.numGen);

Error in frictionGUI>startButton_Callback (line 218)

result = feval(identData.optModel,data,options);

Error while evaluating UIControl Callback.

Thanks in advance.

Answer 1

[Stephan]

Hi,

the line where ga is called

[d endPop trace]=ga([],bounds(:,1),bounds(:,2),linOptFcn,IdentParams,[70 -1],'maxGenTerm',opts.numGen);

is incorrect. The first input argument should be a function handle as the error message tells you. At this position there is an empty array []. The second argument tells ga how many optimization variables are there - there is also no entry. This can not work. It should be something like:

nvars = 1;
lb = 0;
ub = 5;
[d endPop trace] = ga(@(x) sin(x)/x, nvars, lb, ub...)

or

nvars = 2;
lb = [0 -2];
ub = [5  12.6];
[d endPop trace] = ga(@myFitnessFunction, nvars, lb, ub...)

result = function myFitnessFunction(x)
result = x(1).^2 + 3.*x(2) 
end

See the documentation of ga.

Best regards

Stephan