How can I declare a global variable in Matlab for a few functions?

Question

I have a file called histShape.m with a function histShape , and some other functions also .

A general view of the code is :

%
function [outputImage] = histShape(srcimg, destimg)

    PIXELS = 255 + 1;

     ....
     ....
end



%
function [outputImage] = normalizeAndAccumulate(inputImage)

   PIXELS = 255 + 1;

....
....

end

%
function [pixels] = getNormalizedHistogram(histogram , inputImage)


   PIXELS = 255 + 1;

  ....
  ....

end

I can use global x y z; but I'm looking for a different way .

I want to declare the variable PIXELS as global , how can I do that ?

Regards

Answer 1

You can gain access to a global variable inside a MATLAB function by using the keyword global:

function my_super_function(my_super_input)
    global globalvar;

    % ... use globalvar
end

You will usually declare the global variable in a script outside the function using the same keyword:

% My super script
global globalvar;
globalvar = 'I am awesome because I am global';
my_super_function(a_nonglobal_input);

However, this is not strictly necessary. As long as the name of the global variable is consistent between functions, you can share the same variable by simply defining global globalvar; in any function you write.

All you should need to do is define global PIXELS; at the beginning of each of your functions (before you assign a value to it).

See the official documentation here.