[Matlab GUI] Build simple Data Processing tool - 3/5

3. Display variables of mat file, and Plot variables on the axes

After loading a mat file in structure type, click a mat file, and then variables in the mat file selected will appear on the two pop-up menus of X and Y.
With one or two variables selected, we can draw a plot on the axes.

To implement these functions, one is to know each variable saved in a mat file, and the other is to draw a plot with variables selected.

1) Know each variable in a mat file
After clicking a mat file on the listbox, variables in a mat file in the structure type displays on the two pop-up handles.

Create a callback function of the listbox as below.

------------------------------------------------------------------------
function FileList_Callback(hObject, eventdata, handles)
% hObject    handle to FileList (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = cellstr(get(hObject,'String')) returns FileList contents as cell array
%        contents{get(hObject,'Value')} returns selected item from FileList
try
    index = get(handles.FileList,'Value');
    file = get(handles.FileList,'String');
    filename = file(index); filename = filename{1,1};
    filenamePath = fullfile(handles.directory,filename);
catch% ME
    %warndlg(ME.message);
    return;
end

% check a file extension
comma = strfind(filenamePath,'.');
extension = filenamePath(comma(1)+1:end);

switch extension
    case 'mat'     
        result = load(filenamePath); % load structure mat file
        VariableList = fieldnames(result); % extract field names
        handles.result = struct2cell(result);     
        % Display variables on the pop-up of Y       
        set(handles.VariablesList,'String',VariableList);     
        % Display variables on the pop-up of X
        set(handles.xVariables,'String',VariableList);     

handles.legend = filename;
set(handles.selectedFile,'String',filename);
guidata(hObject,handles);
-------------------------------------------------------------------------


2) Draw a plot

% --- Executes on button press in postprocessing
function plot_Callback(hObject, eventdata, handles)
% hObject    handle to postprocessing_ui (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

warning('off');
index = get(handles.VariablesList,'Value');
holdaxis = get(handles.holdon,'Value');
checkp = get(handles.xPlotCheck,'Value'); % x-axis on/off check

% is the plot handles field defined for the handles structure?
if ~isfield(handles,'pline');
    handles.pline = [];% handles.pline will be used afterward.
end

try
    % create a legend name
    tleg = handles.legend(1:end-4);
    yvar = get(handles.VariablesList,'String');
    yvari = get(handles.VariablesList,'Value'); ytemp = yvar(yvari);
    leg = sprintf('%s%s%s',tleg,': ',ytemp{1});

    result = handles.result;
    y = result{index,1};

    % Hold on
    if isequal(holdaxis,1)
        hold(handles.axes1,'all');
        if isequal(checkp,1)% with x-axis variable selected
            xn = get(handles.xVariables,'String');
            xi = get(handles.xVariables,'Value'); xn = xn{xi,1};
            x = result{xi,1};
            pline = plot(handles.axes1,x,y,'DisplayName',leg);
            hl = legend(handles.axes1,'-DynamicLegend');
            xlabel(xn,'interpreter','none');
            ylabel(ytemp{1},'interpreter','none');
        else % default
            pline = plot(handles.axes1,y,'DisplayName',leg);
            hl = legend(handles.axes1,'-DynamicLegend');
            ylabel(ytemp{1},'interpreter','none');
        end         

        set(hl,'Interpreter','none');
 
    % Hold off
    else
        % Initialization of handles.pline
        handles.pline = [];
     
        hold(handles.axes1,'off');
        if isequal(checkp,1)% with x-axis variable selected
            xn = get(handles.xVariables,'String');
            xi = get(handles.xVariables,'Value'); xn = xn{xi,1};
            x = result{xi,1};
            pline = plot(handles.axes1,x,y,'DisplayName',leg);
            hl = legend(handles.axes1,'-DynamicLegend');
            xlabel(xn,'interpreter','none');
            ylabel(ytemp{1},'interpreter','none');
        else % default   
            pline = plot(handles.axes1,y,'DisplayName',leg);
            hl = legend(handles.axes1,'-DynamicLegend');
            ylabel(ytemp{1},'interpreter','none');
        end
        set(hl,'Interpreter','none');
    end
 
    % update the plot handles to the array of plot handles
    handles.pline = [handles.pline ; pline];
    guidata(hObject,handles);
    grid(handles.axes1,'on');
 
    % Save the plot legend
    handles.hl = hl;
    guidata(hObject,handles);
 
catch ME
    warndlg(ME.message,'No data files');
    guidata(hObject,handles);
    %warndlg('Please first load data files','No data files');
end




Related posts
0. Build simple plot tool.
1. Create a tool layout in GUIDE
2. Load mat file in structure array, and Display the file list loaded on the listbox
3. Display variables of mat file, and Plot variables on the axes
4. How to add new plot to the existing plot, and Use dynamic legend
5. Clear the axes, and Move the figure to new figure (Undock)