How to add drop down items based on a categorical array the user inputs in matlab gui app?

% Value changed function: SELECTTEAMDropDown

function SELECTTEAMDropDownValueChanged(app, event)

teamname = string(app.SELECTTEAMDropDown.Value)

disp(app.station_names)

disp(app.trucklist)

% for i=1:12

% val{i}={app.station_names{i}}

% end

class((app.station_names))

app.SELECTSTATIONDropDown.Items=app.station_names

end

Answer 1

[Deepak]

Hi Prajwal,

To resolve the issue of populating dropdown items in a MATLAB GUI app based on a user-provided categorical array, first convert the categorical array to a cell array of strings using the “cellstr” function. This conversion allows to assign the array to the “Items” property of dropdown, ensuring the GUI can display the options correctly. Check if the array is categorical using “iscategorical” before conversion, and if it is already a string or cell array, assign it directly.

Below is the MATLAB code to achieve the same:

% Value changed function: SELECTTEAMDropDown
function SELECTTEAMDropDownValueChanged(app, event)
teamname = string(app.SELECTTEAMDropDown.Value);
disp(app.station_names);
disp(app.trucklist);

% Convert categorical array to cell array of strings
if iscategorical(app.station_names)
    stationNamesCellArray = cellstr(app.station_names);
else
    stationNamesCellArray = app.station_names; % Assume it's already a cell array or string array
end

% Update the dropdown items
app.SELECTSTATIONDropDown.Items = stationNamesCellArray;
end

Please find attached the documentation of functions used for reference:

iscategorical: www.mathworks.com/help/matlab/ref/iscategorical.html

cellstr: www.mathworks.com/help/matlab/ref/cellstr.html

I hope this will help in resolving the issue.