i'm writing an app to read data from excel file and plot the data with matlab app designer, is there any example i can refer to

i need to create a gui where the user can select an excel file with selected path and create plots with with various columns as x and y axes, i also need to provide with an dropdown menu for headings in column, is there any example cases that i can refer to?

Answer 1

[Kojiro Saito]

It's not Excel file, but MATLAB document has an Example of uigetfile and dropdown menu.

You can also open this example by the following command.

openExample('matlab/AppdImageHistogramsExample')

If you want to specify file extensions with .xlsx and read it as a table, the following will work.

[file, path] = uigetfile('*.xlsx');
t = readtable(fullfile(path, file));

UPDATED

I've attached a sample mlapp file (as a zip file) which sets drop down menu from input Excel file.

[vijayagopi r]

i need to provide an drop down menu where the user can read and select each column's id (of the excel file)

i want to know how to address the dropdown menu to the data associated with the excel file

[Kojiro Saito]

I've updated my previous answer and attached a sample mlapp file.

Drop down menu can be created from input file as the following.

[file, path] = uigetfile('*.xlsx');
if isequal(file,0)               
   msgbox('Please input an Excel file')
else
   t = readtable(fullfile(path, file));
   app.UITable.Data = t;
   % Set column names as a pull down menu
   app.xDropDown.Items = t.Properties.VariableNames;
end

[vijayagopi r]

thanks a lot :)

[Harish M]

dear sir,

i want read large csv file. above code is not working for please help...

[Kojiro Saito]

For large CSV files, you can use datastore.

[files, path] = uigetfile('*.csv', 'MultiSelect', 'on');
if isequal(files,0)
    msgbox('Please input CSV files')
else
    ds = datastore(fullfile(path, files));
    while hasdata(ds)
        % Read a chunk as table 
        t = read(ds);
        
        % TBD
        % process t
    end    
end

For detail, here is datastore documentation.

https://www.mathworks.com/help/matlab/import_export/what-is-a-datastore.html

[Laurenz Grigat]

Hi Kojiro,

can you make the code behind your zip file available please? I have a very similar task and want to get some inspiration. Thanks a lot!

[Kojiro Saito]

Hi Laurenz,

Here is a full code of the mlapp file which I had attached previously.

classdef app1 < matlab.apps.AppBase

    % Properties that correspond to app components
    properties (Access = public)
        UIFigure         matlab.ui.Figure
        ReadExcelButton  matlab.ui.control.Button
        UITable          matlab.ui.control.Table
        xDropDownLabel   matlab.ui.control.Label
        xDropDown        matlab.ui.control.DropDown
        UIAxes           matlab.ui.control.UIAxes
        yDropDownLabel   matlab.ui.control.Label
        yDropDown        matlab.ui.control.DropDown
    end

    % Callbacks that handle component events
    methods (Access = private)

        % Button pushed function: ReadExcelButton
        function ReadExcelButtonPushed(app, event)
            [file, path] = uigetfile('*.xlsx');
            if isequal(file,0)               
               msgbox('Please input an Excel file')
            else
                t = readtable(fullfile(path, file));
                app.UITable.Data = t;
                % Set column names as a pull down menu
                app.xDropDown.Items = t.Properties.VariableNames;
                app.yDropDown.Items = t.Properties.VariableNames;
                
                plot(app.UIAxes, app.UITable.Data.(app.xDropDown.Value), app.UITable.Data.(app.yDropDown.Value));
            end
            
        end

        % Value changed function: xDropDown
        function xDropDownValueChanged(app, event)
            value = app.xDropDown.Value;
            
            plot(app.UIAxes, app.UITable.Data.(app.xDropDown.Value), app.UITable.Data.(app.yDropDown.Value));
        end

        % Value changed function: yDropDown
        function yDropDownValueChanged(app, event)
            value = app.yDropDown.Value;
            
            plot(app.UIAxes, app.UITable.Data.(app.xDropDown.Value), app.UITable.Data.(app.yDropDown.Value));
        end
    end

    % Component initialization
    methods (Access = private)

        % Create UIFigure and components
        function createComponents(app)

            % Create UIFigure and hide until all components are created
            app.UIFigure = uifigure('Visible', 'off');
            app.UIFigure.Position = [100 100 640 480];
            app.UIFigure.Name = 'UI Figure';

            % Create ReadExcelButton
            app.ReadExcelButton = uibutton(app.UIFigure, 'push');
            app.ReadExcelButton.ButtonPushedFcn = createCallbackFcn(app, @ReadExcelButtonPushed, true);
            app.ReadExcelButton.Position = [271 427 100 22];
            app.ReadExcelButton.Text = 'Read Excel';

            % Create UITable
            app.UITable = uitable(app.UIFigure);
            app.UITable.ColumnName = {'Column 1'; 'Column 2'; 'Column 3'; 'Column 4'};
            app.UITable.RowName = {};
            app.UITable.Position = [170 287 302 108];

            % Create xDropDownLabel
            app.xDropDownLabel = uilabel(app.UIFigure);
            app.xDropDownLabel.HorizontalAlignment = 'right';
            app.xDropDownLabel.Position = [184 230 25 22];
            app.xDropDownLabel.Text = 'x';

            % Create xDropDown
            app.xDropDown = uidropdown(app.UIFigure);
            app.xDropDown.Items = {};
            app.xDropDown.ValueChangedFcn = createCallbackFcn(app, @xDropDownValueChanged, true);
            app.xDropDown.Position = [224 230 100 22];
            app.xDropDown.Value = {};

            % Create UIAxes
            app.UIAxes = uiaxes(app.UIFigure);
            title(app.UIAxes, 'Title')
            xlabel(app.UIAxes, 'X')
            ylabel(app.UIAxes, 'Y')
            app.UIAxes.Position = [170 32 300 185];

            % Create yDropDownLabel
            app.yDropDownLabel = uilabel(app.UIFigure);
            app.yDropDownLabel.HorizontalAlignment = 'right';
            app.yDropDownLabel.Position = [410 230 25 22];
            app.yDropDownLabel.Text = 'y';

            % Create yDropDown
            app.yDropDown = uidropdown(app.UIFigure);
            app.yDropDown.Items = {};
            app.yDropDown.ValueChangedFcn = createCallbackFcn(app, @yDropDownValueChanged, true);
            app.yDropDown.Position = [450 230 100 22];
            app.yDropDown.Value = {};

            % Show the figure after all components are created
            app.UIFigure.Visible = 'on';
        end
    end

    % App creation and deletion
    methods (Access = public)

        % Construct app
        function app = app1

            % Create UIFigure and components
            createComponents(app)

            % Register the app with App Designer
            registerApp(app, app.UIFigure)

            if nargout == 0
                clear app
            end
        end

        % Code that executes before app deletion
        function delete(app)

            % Delete UIFigure when app is deleted
            delete(app.UIFigure)
        end
    end
end

Answer 2

[mohanambal saminathan]

how to read 12 excel sheets in drop down matlab app designer