Matlab GUI design. Apply logical indexing expression to a loaded file using input values

Hi,

i'm writing a simple GUI that has to be capable of loading a file (this part i already managed), receiving two values from differents EditField and use those values on a logical indexing expression applied to the loaded file. Tipically a row selection on a matrix activated with a "Apply cut" button.

I'm using App Designer on Matlab R2020b.

I've already created all the button and fields. The file is correctly loaded via this function:

function LoadfileButtonPushed(app, event)
[file,path] = uigetfile('*.geo.txt');
 if isequal(file,0)
    disp('User selected Cancel');
 else
    disp(['User selected ', fullfile(path,file)]);
 end
 R=dlmread(fullfile(path , file), ";", 4, 0);
end

and the extremes of the cut are read by those functions:

 function toEditFieldValueChanged(app, event)
  to_value = app.toEditField.Value;
 end

function FromEditFieldValueChanged(app, event)
    from_value = app.FromEditField.Value;  
end

Last, the function related to the "apply cut" button is:

function ApplycutButtonPushed(app, event)
    R_mod=R(from_value:to_value, :); 
end

My problem is that those function does not communicate, and the "Code View" function does not allow me to write a "main function" in which make those functions work together.

Any help would be very appreciated,

thanks in advance.

Answer 1

[Mario Malic]

Hi Alessandro,

yes, these callbacks do not communicate. You can solve this in a much simpler way, remove 'to' and 'from' callbacks completelly.

You don't need to create a callback to be able to track the property values in the component.

function ApplycutButtonPushed(app, event)
    to_value = app.toEditField.Value;
    from_value = app.FromEditField.Value;  
    R_mod=R(from_value:to_value, :); 
end

If you have a more complicated case, where you'd do some calculations inside a callback, you can create a property that you'll assign the calculated value. Property is accessible everywhere within and outside of app (if properties are declared as public). You set/access the property values indexing into app like shown in callback.

properties(access = private)
    R
end

function SomeCallback(app,event)
    app.R=dlmread(fullfile(path , file), ";", 4, 0);
end

Edit: you could use the same principle as I've just mentioned just above this line which I've just edited.

Answer 2

[Alessandro Togni]

This solves a big part of the problem, but still the variable R created on the LoadfileButtonPushed function is not reacheable in ApplycutButtonPushed.