Callback function with pushbutton option

Hi all,

I'm trying to configure an uicontrol gui of pushbutton type. I would like to create several pushbuttons and depending which one is pressed, the code will execute a specific function. I have problems to build the function. I'm new on this staff.

My code is:

 ad=uicontrol('Style', 'pushbutton', 'String', 'Addition Beam','Position', [20 20 80 30],'Callback', @addition);

 function addition

 for j= 1:p
         if J(j) == 2 || J(j) == 3,
         J(j) = 0;
         end
 end    
end

When the user clicks on the generated button 'Addition Beam', the function addition should be activated.

Thanks for your help.

Best regards,

Raúl.

Answer 1

[Jan]

This happens already: When the button is called, the function addition is called. But Matlab provides two standard inputs as default, so you need:

   function addition(ObjectH, EventData)
   for j = 1:p
     if J(j) == 2 || J(j) == 3,
       J(j) = 0;
     end
   end    
   end

But now the next occurring problem is, that neither p nor J are known inside this function. Any function has its own workspace and if you want to share a variable, you have to do this explicitly (together with a "vectorized" solution):

   function addition(ObjectH, EventData)
   handles = guidata(ObjectH);  % Get struct from figure
   J = handles.J;
   J(J == 2 | J == 3) = 0;
   handles.J = J;
   guidata(ObjectH, handles);  % Put struct to figure
   end

[Raúl]

Thanks Jan,

It still appears wrong with the error: FUNCTION keyword use is invalid here. This might cause later messages about END.

And this error in the Command Windows: Function definitions are not permitted in this context.

My code is now:

 ad=uicontrol('Style', 'pushbutton','String', 'Addition Beam','Position', [20 20 80 30],'Callback', @addition);

function addition (ObjectH, EventData)
handles = guidata(ObjectH);  % Get struct from figure
 J = handles.J;
 J(J == 2 | J == 3) = 0;
 handles.J = J;
 guidata(ObjectH, handles);  % Put struct to figure
end

Thanks again.

Raúl

[Jan]

Please post an exact copy of the complete error message. If Matlab moans about the function keyword, usually somebody tries to define a function inside a script or in the command window. But functions are allowed as main or sub-function in an M-file only. Therefore I thought your code is only a fragment of a larger M-file, but perhaps it is not. Are you working with GUIDE? Do you know the difference between scripts and functions?