how to Make a button upload a .txt file and another button to read the file and plot it in matlab app design?

Do you have any tips in making my buttons work, i did the code in normal matlab and it works but i dont know how to translate it in app designer

1. the code in calculate button should plot a line graph showing the peaks

This is for my upload button, it should keep the file "data.txt"

      % Button pushed function: UploaddataButton
        function UploaddataButtonPushed(app, event)
            [file,path] = uigetfile('*.txt')
        end

This is for my "calculate" button, the code should read the uploaded file and plot the graph

        % Button pushed function: CalculateButton
        function CalculateButtonPushed(app, event)
            fid=fopen('Data.txt');

s=textscan(fid,'%f %f','headerlines',2);

g = cell2mat(s);

x=g(:,1);
y=g(:,2);

[sortedX, sortIndex] = sort(x);
sortedY = y(sortIndex);
          sortedXLimit = sortedX(1:160,:);
          sortedYLimit = sortedY(1:160,:);


findpeaks(sortedYLimit,sortedXLimit,'MinPeakProminence',205,'Annotate','extents')

[psor,lsor] = findpeaks(sortedYLimit,sortedXLimit,'MinPeakProminence',205,'SortStr','descend')

set(gca, 'XDir','reverse')

text(lsor+.02,psor,num2str((1:numel(psor))'))
        end

Answer 1

[Adam Danz]

When you select the file with uigetfile, the outputs need to be stored as a property of the App so all callback functions have access to the files selected.

Here's instructions how to set the file and path variables as app properties and here's a demo you can follow.

In your CalculateButtonPushed function, after the file and path variables have been declared as properties, you can access the user's selection:

 fid=fopen(fullfile(app.Path, app.File));
 %                  ^^^^^^^^  ^^^^^^^^^  replace with your var names

[sydney salvador]

thank you , i will try now

[sydney salvador]

Hello thank you I have no problem with the properties but can I ask you again with the "fid=fopen" i dont understand understand what i should put in "app.File" my code below says there is an error, i have placed a "plot" command for UI axes in the last part to show the graph of data

 properties (Access = public)
        selectpath='';
    end
    

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

        % Button pushed function: UploadButton
        function UploadButtonPushed(app, event)
            [file,path] = uigetfile('*.txt')
        end

        % Button pushed function: CalculateButton
        function CalculateButtonPushed(app, event)
fid=fopen(Data.txt(app.selectpath));
fclose(fid);                                    %Error using textscan 
                                                % Invalid file identifier. 
                                                % Use fopen to generate a valid file identifier.
seek=textscan(fid,'%f %f','headerlines',2);

g = cell2mat(seek);

x=g(:,1);
y=g(:,2);

[sortedX, sortIndex] = sort(x);
sortedY = y(sortIndex);
          sortedXLimit = sortedX(1:160,:);
          sortedYLimit = sortedY(1:160,:);

plot(app.UIAxes,value*peaks)                %for the graph
app.UIAxes.YLim = [0 205];

[Adam Danz]

My understanding is that this function,

        function UploaddataButtonPushed(app, event)
            [app.file, app.path] = uigetfile('*.txt')
        end

allows the user to select a file and the outputs are stored as properties of the app. The that file is read by,

         fid=fopen(fullfile(app.Path, app.File));