How to count the number of times I called a function (using the command line)

Hi,

The backstory: So I'm trying to design an image analysis tool on App Designer where I "feed" an image through a function, do some analysis in my function, output numerical results, verfiy to see if the analysis was done correctly visually, save the function outputs into a spreadsheet, and repeat the process with a different image. The first time the function is called, the results will be stored in the first row of the array; the second time it is called it will be stored in the second row of the array so on and so forth. I figured that to do this, I need to have someway to keep track of how many times my function is called. So I'm testing this with a simpler example:

function p = myfunction(a,b,c)
counter=0; %Initializing counter
parabola

   function parabola
   e = a+5
   f = b+10
   g= c+100
   store=[e,f,g] %Still figuring out how to define the row associated with the counter to store my variable
   
   end
counter = counter+1
end

However, I'm at to how I can not make the counter reset everytime I pass a new function.

For instance, if I were to do myfunction(1,2,3) followed by myfunction(2,3,4) I would still get counter =1.

Any help for this novice will be highly appreciated!!

Answer 1

[per isakson]

You could replace

counter=0; %Initializing counter

by

persistent  counter
if isempty( counter )
    counter=0; %Initializing counter
end

However, don't you have the same problem with store ?

[William Pang]

Thanks for your answer. That's a good point as well; I tried and I'm seeing similar problems (i.e. the first row of my store matrix gets set to 0)

function p = myfunction(a,b,c)
    persistent  counter
    if isempty( counter )
    counter=0; %Initializing counter
    end
    
    store=zeros(10,3) %I guess the number of rows doesn't really matter
    
    parabola
    

   function parabola
   e = a+5
   f = b+10
   g= c+100
   
   store(counter+1,:)=[e,f,g]
   
   end
counter = counter+1
end

Maybe there is a more elegant solution that I'm not seeing?

[per isakson]

"save the function outputs into a spreadsheet" does that mean that you eventually will want to transfer the content of store to the spreadsheet?

Now the current value of store will be lost every time myfunction is finished. The output p isn't set.

Why not write directly to the spreadsheet? A bit slow but ...

The more elegant solution is based on a class with method to add rows, write to spreadsheet, and it will take care of the counter.

Answer 2

[Steven Lord]

Since you're doing this as part of an App Designer app, why not store the iteration count in a property of your app? As long as you have a handle to the app in one of the functions being called, it can either retrieve and update that property directly or pass the property value into a function that's not an app method, receive an updated value from that function when it returns, and store the updated value back into the property.

[William Pang]

Thanks Steven for the suggestion! I tried it and it works. However, I'm still facing one problem:

%Passes through RangeFilter Function
           [s, per, I_bin_regions_show] = rangefiltertest(app.I_M,filter_size, Thresh, cut_cells_regions); %My function
           app.ValueEditField.Value = num2str(s); %Displays sum into box — to be placed in excel
           app.PercentCoverageEditField.Value = num2str(per); %Displays percentage into box — to be placed in excel
           
           %Store Image
           store(app.TotalCount,:) = [s, per]
           writematrix(store,'RangeFilterData.xls')

where I have the app.TotalCount linked to a button in my App Designer:

  %Clears boxes when "Next" is pressed
        app.UIAxes.cla;
        app.UIAxes_2.cla;
        app.ValueEditField.Value = '';
        app.PercentCoverageEditField.Value ='';
        
        %Increment Display
        app.TotalCount = app.increment();
        app.Label.Text=num2str(app.TotalCount);

Here's a snapshot of my UI:

The idea is whenever you load an image, it will run through my function and give out two numbers (values and percent coverage) that I want stored in my Excel sheet. Once you click "next", you clear the screen, and then you can load a new image and repeat the same analysis. Once you've completed, all the data would ideally be saved into an excel sheet.

However, when I try to upload the second image:

store(app.TotalCount,:) = [s, per]
writematrix(store,'RangeFilterData.xls')

I see the data is all messed up on my excel sheet:

Any help would be appreciated!!!

Answer 3

[Ranitha Mataraarachchi]

Hi. Maybe you found yourself a way out. But you could've defined the 'counter' as a global variable and increment the counter inside the function.