Making a nested function in within a script for a call back function

I am learning how to program a GUI programatically. I have a script called plotburst that i need to write a nested function called randomize within. I want to set randomizr as the callback function for my button. I also need to set the postion and apperance of a plotted data point to random values. I'm not sure on how to even start this problem if you could help that would be great.

[Jan]

"I'm not sure on how to even start" - This is hard to answer. Maybe install Matlab? Or buy a computer? Did you read Matöab's Onramp tutorial already?

Do you create a figure or uifigure? Do you write it by functions or object oriented?

Do not start with nested subfunctions having a specific name but just open a figure, create a button and let the callback print "hello world". Then expand the code. Post the code to aks specific questions.

[Amanda]

f= figure;
ax= axes('Parent',f,'Position',[0.05, 0.25, 0.9, 0.7]);
xlim = [0 1];
ylim = [0 1];
x = 0.25;
y = 0.55;
point_plot_handle = plot(x,y,'d','MarkerFaceColor','m','MarkerSize',75);
hold on;
my_button = uicontrol('style','pushbutton');
set(my_button, 'units', 'normalized', 'position', [0.05,0.05,0.3,0.15])
set(my_button, 'string','Add Point')
my_second_button = uicontrol('style','pushbutton');
set(my_second_button, 'units', 'normalized', 'position', [0.35,0.05,0.3,0.15])
set(my_second_button, 'string', 'Clear')
my_third_button = uicontrol('style', 'pushbutton');
set(my_third_button, 'units', 'normalized','position', [0.65,0.05,0.3,0.15])
set(my_third_button, 'string', 'Randomize')
set(my_third_button, 'callback', @sayrandomize)

This is what I have so far. I am aware that app designer would be easier but it for an assingment and this is how my professor has asked us to do it. I would just like some help not saracasm, thanks in advance

[Jan]

Okay, now it is getting clearer.

Do you really want a "nested function"? This is not possible inside a script. Convert the script to function, which is a good strategy to write reliable code at all.

Nested functions share data with the surrounding function. This can be useful or confusing. If nesting is not required, prefer a standard function and share the data e.g. by guidata():

function sayrandomize(ButtonH, EventData)

end

What does this exactly mean: "I also need to set the postion and apperance of a plotted data point to random values"?

[Amanda]

It is suppose to be a nested function 'randomize' within 'plotBurst'. Then I need to Set randomize as the callback function for the button labeled “Randomize”. In the function, I need to set the position and appearance of the plotted data point to random values with a reasonable range.So I need to take the plotted point and make it randomize when I press the button.

[Walter Roberson]

@Jan

Nested functions are permitted within scripts, as long as they are nested within a function.

try_experiment()

ans = 62

function result = try_experiment
   shared_variable = 0;
   for K = 1 : 5; try_nested(); end
   result = shared_variable;
   
    function try_nested
        shared_variable = (shared_variable + 1) * 2;
    end
end

[Jan]

@Walter Roberson: Thanks for the clarification.

@Amanda: "It is suppose to be a nested function 'randomize' within 'plotBurst'" - So start to write 'plotBurst' t first.

"I need to set the position and appearance of the plotted data point to random values with a reasonable range" - I cannoit guess, what you calle "the plotted data point".

The explanations are too abstract to suggest some specific code. So just a general hint: I think it is easier to read, if the parameters of a uicontrol are set directly. Compare:

my_third_button = uicontrol('style', 'pushbutton');
set(my_third_button, 'units', 'normalized','position', [0.65,0.05,0.3,0.15])
set(my_third_button, 'string', 'Randomize')
set(my_third_button, 'callback', @sayrandomize)

with

my_third_button = uicontrol('style', 'pushbutton', 'string', 'Randomize', ...
              'units', 'normalized','position', [0.65, 0.05, 0.3, 0.15], ...
              'callback', @sayrandomize);

Simpler code reduces the chance to insert typos and increases the chance to find them.

Answer 1

[Mohsin Zubair]

Not sure about the content of your code so can't answer the later part but for 1st part about to create a button and assign a userdefined function as its call back you can do it like this:

f=uifigure;
uibutton(f,"ButtonPushedFcn",@randamize);

You can set position of button using "Position" property in above line.

But for working with GUI I woud suggest use App Designer instead.

[Amanda]

I have posted my code above if that helps

[Mohsin Zubair]

@Amanda @Jan has explained it much better already