i have uploaded a table. how can i read it to a table? my next step is to do a table2array. Problem is it that i cant find out where should i begin to

classdef SToRM_20211208 < matlab.apps.AppBase
    
    % Properties that correspond to app components
    properties (Access = public)
        UIFigure             matlab.ui.Figure
        Label                matlab.ui.control.Label
        SToRMLabel           matlab.ui.control.Label
        SimulationdesTorsionsverhaltenseinesRotorstrangsmitMATLABLabel  matlab.ui.control.Label
        CalculatefeigButton  matlab.ui.control.Button
        UITable              matlab.ui.control.Table
        CheckDataButton      matlab.ui.control.Button
        UploadTableButton    matlab.ui.control.Button
        UIAxes               matlab.ui.control.UIAxes
    end
    
    
    properties (Access = public)
        
        %Variables
        data;                                         %Enthält die eingelesenen Daten, die den Körper beschreiben
        error;
        
        %Function Handler
        DataImport = @function_DataImport;         %Funktion zum Import der DataMatrix
        DataCheck = @function_DataCheck;
        
    end
    
    
    
    %     methods (Access = private)
    %         
    %         function check(app)
    % 
    %             error = app.DataCheck;
    % 
    % %             app.ErrorOutputTextfield.Value = Error;       %Add Error-Output field here
    %             
    %         end
    %     end
    
    
    % Callbacks that handle component events
    methods (Access = private)
        
        % Code that executes after component creation
        function startupFcn(app)
            clc
            
            %Diabling all Buttons 
            app.CheckDataButton.Enable = 'off';
            app.CalculatefeigButton.Enable = 'off';
            app.UITable.Enable = 'off';
        end
        
        % Button pushed function: UploadTableButton
        function UploadTableButtonPushed(app, event)
            
            dataMatrix = DataImport; 
            
            app.UITable.Data = dataMatrix;
            
            app.data = dataMatrix;
            
            %Enabling all Buttons 
            app.CheckDataButton.Enable = 'on';
            app.CalculatefeigButton.Enable = 'on';
            app.UITable.Enable = 'on';
        end
        
        % Display data changed function: UITable
        function UITableDisplayDataChanged(app, event)
            newDisplayData = app.UITable.DisplayData;
        end
        
        % Button pushed function: CheckDataButton
        function CheckDataButtonPushed(app, event)
            
            data = app.data
            
            app.error = DataCheck(data);
            
            error = app.error
            
        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 = [100 100 963 714];
            app.UIFigure.Name = 'MATLAB App';
            
            % Create UIAxes
            app.UIAxes = uiaxes(app.UIFigure);
            title(app.UIAxes, 'Title')
            xlabel(app.UIAxes, 'X')
            ylabel(app.UIAxes, 'Y')
            zlabel(app.UIAxes, 'Z')
            app.UIAxes.Position = [201 369 734 266];
            
            % Create UploadTableButton
            app.UploadTableButton = uibutton(app.UIFigure, 'push');
            app.UploadTableButton.ButtonPushedFcn = createCallbackFcn(app, @UploadTableButtonPushed, true);
            app.UploadTableButton.Position = [28 571 100 22];
            app.UploadTableButton.Text = 'Upload Table';
            
            % Create CheckDataButton
            app.CheckDataButton = uibutton(app.UIFigure, 'push');
            app.CheckDataButton.ButtonPushedFcn = createCallbackFcn(app, @CheckDataButtonPushed, true);
            app.CheckDataButton.Position = [28 517 100 22];
            app.CheckDataButton.Text = 'Check Data';
            
            % Create UITable
            app.UITable = uitable(app.UIFigure);
            app.UITable.ColumnName = {'Type of element'; 'Length'; 'Radius 1'; 'Radius 2'; 'Rho'; 'G-Value'};
            app.UITable.RowName = {};
            app.UITable.DisplayDataChangedFcn = createCallbackFcn(app, @UITableDisplayDataChanged, true);
            app.UITable.Position = [239 117 688 253];
            
            % Create CalculatefeigButton
            app.CalculatefeigButton = uibutton(app.UIFigure, 'push');
            app.CalculatefeigButton.Position = [28 459 100 22];
            app.CalculatefeigButton.Text = 'Calculate f eig';
            
            % Create SimulationdesTorsionsverhaltenseinesRotorstrangsmitMATLABLabel
            app.SimulationdesTorsionsverhaltenseinesRotorstrangsmitMATLABLabel = uilabel(app.UIFigure);
            app.SimulationdesTorsionsverhaltenseinesRotorstrangsmitMATLABLabel.FontAngle = 'italic';
            app.SimulationdesTorsionsverhaltenseinesRotorstrangsmitMATLABLabel.Position = [157 666 368 28];
            app.SimulationdesTorsionsverhaltenseinesRotorstrangsmitMATLABLabel.Text = {'Simulation des Torsionsverhaltens eines Rotorstrangs mit MATLAB'; 'Simulation of the torsional behavior of a rotor strand with MATLAB '};
            
            % Create SToRMLabel
            app.SToRMLabel = uilabel(app.UIFigure);
            app.SToRMLabel.FontSize = 32;
            app.SToRMLabel.Position = [28 660 110 39];
            app.SToRMLabel.Text = 'SToRM';
            
            % Create Label
            app.Label = uilabel(app.UIFigure);
            app.Label.Position = [7 645 983 22];
            app.Label.Text = '______________________________________________________________________________________________________________________________________________';
            
            % 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 = SToRM_20211208
            
            % Create UIFigure and components
            createComponents(app)
            
            % Register the app with App Designer
            registerApp(app, app.UIFigure)
            
            % Execute the startup function
            runStartupFcn(app, @startupFcn)
            
            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 1

[Walter Roberson]

        DataImport = @function_DataImport;         %Funktion zum Import der DataMatrix

That is a function handle.

       dataMatrix = DataImport; 

dataMatrix will be a copy of the function handle. You are not invoking the function, you are just copying the handle.

If you had named function_DataImport directly, as in

       dataMatrix = function_DataImport;

then that would have been an invocation of the function with no parameters. But automatic invocation does not happen for function handles, only for direct function names.