How to run a matlab function using a button pushed in AppDesigner

Hello everyone,

My question is simple. I want to run a function in matlab base workspace using a button pushed in AppDesigner.

I added a button in my app, and create a callback with this instruction :

run ('Path of my function');

My function is (just for the test) :

function r=addition(a,b)
    r=a+b;
end

Thank you in advance.

[Jan]

This function has 2 inputs. Hwich inputs do you provide when you define the callback?

[Myssipsa Mehraz]

I'm not sure I understand your question, but this is my code in AppDesigner and below the interface I created.

Thanks.

[Matt J]

@Myssipsa Mehraz There's no reason the callback code you've posted wouldn't work. It's just an unnecessarily awkward style of programming.

[Myssipsa Mehraz]

Thank you for answer, but the code I posted is not the code i'm using, it's just a simple example. In my case, i'm developping an graphic interface to control a machine. And i have some functions that realizes the displacement of a support in the machine. For the moment, to do the move I want, I have to use the interface to indicate the values and positions, after that I report them to the base workspace with assignin command and then I execute the predefined code. This method is not very pratical, so I wanted to run this code from a button in the graphic interface directly.

I am attaching an image of the interface and a part of the code of the function so that you can better understand my problem.

%This function performs the movement needed to make measurements according to a cylindrical shape with a circular section
%with the rotation of the azimuth motor

function [vect_phi,vect_x,vect_z]= meas_cylindrical_circular(mot,motAz,rho,X_center,X_step,Y_center,H,Z_center,Z_step,phi_step)
        
        % Computation of the limits
        X_end = X_center - rho;
        Z_end = H + Z_center;
        
        
        % Vector declaration
        vect_phi= 180:phi_step:-180;
        vect_z  = Z_end:Z_step:Z_center;
        vect_x  = X_center:X_step:X_end;
        
        
        
        % Taking the probe to the first measurement point
        move_x(mot,X_center);
        move_y(mot,Y_center);
        move_z(mot,Z_end);
        
        
        % Measure and move
        for interm_phi=1:1:length(vect_phi)-1
                
            % Azimuth motor
            move(motAz,vect_phi(interm_phi));
            pause(5);
           
            % Displacement along the x axis for the high horizontal section of the cylinder
            for interm_x= 1:1:length(vect_x)   
                move_x(mot,vect_x(interm_x));               
                pause(5);                                      % Break during measurement time
            end 
            
           % Displacement along the z axis  
           for  interm_z=1:1:length(vect_z) 
                move_z(mot,vect_z(interm_z));
                pause(5);                                       % Break during measurement time
           end     
           
                                
            % Back to the starting point    // RESPECT ORDER OF MOVING FOR SECURITY
            move_z(mot,Z_end);
            pause(4);
            move_y(mot,Y_center);
            move_x(mot,X_center);
       
        end
     
        
        % Back to absolute zero            // RESPECT ORDER OF MOVING FOR SECURITY
        move_z(mot,0);
        move_y(mot,0);
        move_x(mot,0);
        home (motAz);

So the Validate button allows me to take the values of the variables in the editfields to the base workspace as global variables and then I run the function. I want the "launch" button to execute the function after pressing the "validate" button.

By the way, I found this forum which talks exactly about what I need but it didn't work for me.

https://fr.mathworks.com/matlabcentral/answers/465219-using-app-designer-how-do-i-execute-m-files-in-the-main-workspace

Thank you in advance.

[Jan]

Using assignin to create variables in the base workspace and calling a script is a shot in your knee. Convert the script into a function and provide the variables as input arguments. Then it is very easy to call your function from inside the callback of a GUI.

[Myssipsa Mehraz]

I tested it and it works. Thank you.

Answer 1

[Matt J]

The typical way would be to invoke addition() from your callback the way you would from any ordinary function,

function ExecuterButtonPushed(app,event)
  a=app.aEditField.Value;
  b=app.bEditField.Value;
  
  r=addition(a,b);

end

[Myssipsa Mehraz]

This is just an exemple. In reality, I have to run a machine with a function i defined for it, and i want to launch this machine and its movement without executing the function in matlab but with pressing a button.

I just want to know how to do the link between the button and a function in matlab workspace.

[Jan]

@Myssipsa Mehraz: Matt's example does show you, how the function addition is called from inside the callback. This should solve your problem.

[Myssipsa Mehraz]

@Jan No, this didn't solve my problem. In my case i want to run the function which is in the workspace by pressing a buttonPushed in AppDesigner. So this is not a solution for me.

I know that there's a way to run matlab functions by pressing buttons in AppDesigner without invoking the function in the callback of the ButtonPushed.

[Jan]

Functions are not "in a workspace", but only variables. Remember, that each function has its own workspace, so there is no "the" workspace.

I does not make a sense to me to "run a Matlab function" triggered from a GUI element, without calling it from the callback function. In ancient Matlab versions the callbacks could be defined as CHAR vectors and then they are eval'ed in the base workspace, but this was prone to bugs and hard to debug.

I really do think, that Matt has posted the solution already. So please think about it a third time. If this does not match your needs, please explain exactly again, what you want to achieve.

In your screenshot you show a method to run a script in the base worksspace. This is a fragile approach, because scripts can interfere with the caller in many ways. Prefer to use functions instead, which have a clean list of inputs and outputs.

[Myssipsa Mehraz]

@Jan : Thank you for your answer. I posted a comment in the answer of @Matt J where i explain more what i need to do. Maybe it will be more clearly with this explanations.

[Matt J]

Maybe it will be more clearly with this explanations.

I'm afraid not. What you have not explained is why the machine you are controlling needs to receive its instructions from a Matlab script as opposed to an mfunction. As Jan points out, you could easily convert your script to a function and invoke that function directly from the callback, as my original answer suggests.

Also, even if you insist on using a script, it is not clear what problems you are currently experiencing by running your script from the callback. I can only guess it is because there are additional variables that the script needs besides the EditField values and which reside in the base workspace. If so, why not just bring those extra variables into the app where the callback can see them? Make them inputs to the app constructor and store them in properties.