Is it possible to write methods that iteratively process each element of an objectarray without writing for-loops each time?

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zhehao.nkd 2021-4-8

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评论： Matt J 2021-4-8

If I have such an objectarray:

classdef ObjectArray
   properties
      Value
   end
   methods
      function obj = ObjectArray(F)
         if nargin ~= 0
            m = size(F,1);
            n = size(F,2);
            obj(m,n) = obj;
            for i = 1:m
               for j = 1:n
                  obj(i,j).Value = F;
               end
            end
         end
      end
   end
end

An instance A is created as:

F = magic(5); 
A = ObjectArray(F);

And I would like to calculate the mean, the max, or do whatever calculations based on each obj.Value, then is it possible to write methods without iterations in each of them?

I expect something like this:

function obj = get.mean(obj)
    obj.mean = mean(obj.value)
end

but apparently it doesn't work.

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Answer 1

Matt J 2021-4-8

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编辑：Matt J 2021-4-8

在 MATLAB Online 中打开

It is not possible in a get.property() method, but it is possible in a normal method.

function meanValues = mean(Objects)
    meanValues = arrayfun( @(ob)mean(ob.Value,'all') , Objects);
    
end

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zhehao.nkd 2021-4-8

编辑：zhehao.nkd 2021-4-8

Thank you so much! So at least (1) a function handle and (2) arrayfun() is needed, just like how a normal cell object was treated.

Matt J 2021-4-8

在 MATLAB Online 中打开

Thank you so much!

You're quite welcome, but please click "Accept" if this addressed your problem.

So at least (1) a function handle and (2) arrayfun() is needed, just like how a normal cell object was treated.

It is one solution. If obj.values are all matrices of the same size, you could also have done ,

function meanValues = mean(Objects)
    meanValues=mean( cat(3,Objects.Values)  , [1,2]);
    
    meanValues=reshape(meanValues,size(Objects));
    
end