xlsread in matlab app designer

Hi I am trying to do xlsread in my matlab app designer. All I did was copy and paste:

series1=xlsread('Copy of Shaker Table Descaling Spreadsheet v10292018.xlsx',1)
series2=xlsread('Copy of Shaker Table Descaling Spreadsheet v10292018.xlsx',3)
series3=xlsread('Copy of Shaker Table Descaling Spreadsheet v10292018.xlsx',5)
 rinse1=series1(18:26,1);
 rinse2=series2(15:23,1);
 rinse3=series3(15:23,1);
  dM1=series1(18:26,2:end);
  dM2=series2(15:23,2:end);
dM3=series3(15:23,2:end);

But it's giving me an error message: Invalid default value for property 'rinse1' in class 'descaling_app':

Undefined function 'series1' for input arguments of type 'double'.

[Cris LaPierre]

Is the xlsx file in the same folder as your app? Actually, that would give a different obvious error message. It's complaining about the value assigned to rinse1 and it thinks series1 is a function.

Have you defined series1 or rinse1 anywhere else?

[Stetson Spencer]

yes it is

[Stetson Spencer]

Well I was playing around with series1 earlier in the Matlab command window.

What I was trying to do is see which cells the data was going to be in once i put the excel cell format into matlab's cell format.

once I got the location of each data in each cell I just simply copied and pasted what you see up there under the properties (access=private) in the app designer code view

Answer 1

[Cris LaPierre]

Under properties? That's the issue. I can now duplicate your error message.

Properties is for defining variables. If you want to run code, add it to a function. It can be a callback related to a button press or a helper function. If this is how you want things to start, consider placing it in the startupFcn Callback.

properties (Access = private)
    series1;
    rinse1;
    dM1;
end
    
    ...
        
methods (Access = private)

    % Button pushed function: Button
    function ButtonPushed(app, event)
        
        app.series1=xlsread('test.xlsx',1)
        app.rinse1=app.series1(18:26,1);
        app.dM1=app.series1(18:26,2:end);

    end
end

If the variables are declared in Properties, they exist on the app structure and are passed into all functions. If you don't need them to be available outside the function, you could also just declare them within the function itself.

methods (Access = private)

    % Button pushed function: Button
    function ButtonPushed(app, event)
        
        series1=xlsread('test.xlsx',1)
        rinse1=series1(18:26,1);
        dM1=series1(18:26,2:end);

    end
end

Note that the code here executes in response to a button push in the app, so is added to the ButtonPushed callback function.

Answer 2

[Guillaume]

You probably need to learn a bit more about class design in matlab. Indeed, the code you have written cannot be put in the properties section of the class definition. You are in effect declaring the class properties with some default values, but as documented, expressions for default values cannot reference other variables.

A better design would be to have, in the properties section, just:

properties (Access = private)
    series1;
    series2;
    series3;
    rinse1;
    rinse2;
    rinse3;
    dM1;
    dM2;
    dM3;
end 

and then add a startup function to your app with:

function startupFcn(app)
    app.series1=xlsread('Copy of Shaker Table Descaling Spreadsheet v10292018.xlsx',1)
    app.series2=xlsread('Copy of Shaker Table Descaling Spreadsheet v10292018.xlsx',3)
    app.series3=xlsread('Copy of Shaker Table Descaling Spreadsheet v10292018.xlsx',5)
    app.rinse1=series1(18:26,1);
    app.rinse2=series2(15:23,1);
    app.rinse3=series3(15:23,1);
    app.dM1=series1(18:26,2:end);
    app.dM2=series2(15:23,2:end);
    app.dM3=series3(15:23,2:end);
end

And since numbered variables are a bad design, even better would be:

properties (Access = private)
    series;
    rinse;
    dM;
end

function startupFcn(app)
    %constants
    sheets = [1; 3; 5]
    ranges = [18 26; 15 23; 15 23];
    %initialisation
    app.series = cell(size(sheets));
    app.rinse = cell(size(sheets));
    app.dM = cell(size(sheets))
    %loading 
    for i = 1:numel(sheets)
        app.series{i} = xlsread('Copy of Shaker Table Descaling Spreadsheet v10292018.xlsx', sheets(i))
        app.rinse{i} = series{i}(ranges(i, 1):ranges(i, 2), 1);
        app.dM{i} = series{i}(ranges(i, 1):ranges(i, 2), 2:end);
    end
end

This latter approach has the advantage that if you want to add series, you don't have to modify the code, just edit the two constants sheets and ranges.