How to Plot a graph, from selected items of columns in Matlab appdesigner.

I have created the app which reads a '*.xlsx' file into UITable. There are 2 dropdown options to select particular column of UITable. Lets say Dropdown 1 = x column, Dropdown 2 = ycolumn, I need to plot a graph using values from 100th row to till 200th row only of both columns. Please explain with an example.

Answer 1

[Deepak]

Hi @veeresh nashimath, from my understanding, you have an app designer code that reads a “.xlsx” file and displays the data in a UI Table. The app has two dropdowns named “x-axis” and “y-axis” that show two columns of UI Table. Now, you want to plot the dropdown data from the 100th row to the 200th row on the push button callback.

To do this, we can modify the “PlotButtonPushed” callback to use the “FromEditField” and “ToEditField” inputs. These inputs will determine the range of rows to be used for plotting the selected columns from the UI Table. We can then pass the “FromRow” and “ToRow” row numbers to “table2array” method to convert the required data rows into arrays to plot. Finally, we can use “plot” method to create the desired graph.

Here is the MATLAB code for “PlotButtonPushed” method:

function PlotButtonPushed(app, event) 

    % Get the selected range from the edit fields 
    fromRow = app.FromEditField.Value; 
    toRow = app.ToEditField.Value; 

    % Get the selected columns from the dropdowns 
    xColumnName = app.xAxisDropDown.Value; 
    yColumnName = app.yAxisDropDown.Value; 

    % Ensure the range is valid 
    if fromRow < 1 || toRow > height(app.UITable.Data) || fromRow > toRow 
        uialert(app.UIFigure, 'Invalid row range specified.', 'Error'); 
        return; 
    end 

    % Extract the data for the specified range and columns 
    xData = table2array(app.UITable.Data(fromRow:toRow, xColumnName)); 
    yData = table2array(app.UITable.Data(fromRow:toRow, yColumnName)); 

    plot(app.UIAxes, xData, yData); 
    xlabel(app.UIAxes, xColumnName); 
    ylabel(app.UIAxes, yColumnName); 
    title(app.UIAxes, sprintf('Plot of %s vs %s', yColumnName, xColumnName)); 
end 

Below is the documentation of “table2array” method for reference:

https://www.mathworks.com/help/matlab/ref/table2array.html

I hope this will solve the problem.