Copy fields from object cell array into struct array

Hi everyone,

I have a cell array of cfit objects, let's call it objArray. I want to copy several fields (or I guess I should call them attributes) from this objArray to build a struct array. I know I can do it the following way :

mystruct = cellfun(@(x) struct('field1',x.field1,'field2',x.field2), objArray,'UniformOutput',true);

However I would like a way of doing this with a function that takes as input objArray as well as a cell array containing the names of the fields I am willing to copy. It would look like this :

mystruct = obj2struct(objArray,fieldNames);

Any help is welcome :) thanks

Answer 1

[Matt J]

I would just keep it simple and use a for-loop. There will be no performance gains from doing it some other way. Any abbreviation of this using cellfun or arrayfun will be syntactic sugar at best.

function mystruct = obj2struct(objArray,fieldNames)

    M=numel(objArray);
    N=numel(fieldNames);
    
    for m=M:-1:1
        for n=1:N
            field=fieldNames{n};
            mystruct(m).(field)=objArray{m}.(field);
        end
    end

end

[Hugo Fluhr]

thanks for your help, indeed this seems to be the best solution

[Hugo Fluhr]

I just noticed that your outer for loop loops from the end of the obj array to the start, any particular reason for this?

[Matt J]

It avoids mystruct growing in length throughout the loop, which is inefficient. With a descending loop, the whole mystruct array will be allocated once the first outer iteration completes.