MATLAB: Looping within a structure

loopMATLABstructstructures

Hello everyone,
Sorry if this question was already asked, but I couldnt find something that worked for me. I have the following Matlab struct
mystruct
    point1 : struct
    point2 : struct
    .
    .
    .
    .
    pointN : struct
Basically a structure containing point coordinates,
what I wish to do is basically fetch the data of the structure in a loop. Unfortunately I wasnt able to achieve this. What I created was
for i = 1:N
varName = strcat('mystruct.point',int2str(i));
%fetch data using the varname
end
Basically this is a snippet out of a bigger codeflow which I have simplified for the sake of my question.
Regards,
Sanjay

Best Answer

You can easily loop over the fieldnames:
F = fieldnames(mystruct);
for k = 1:numel(F)
    A = mystruct.(F{k});
    ... do whatever with A
end
or use numbers to generate the fieldnames:
for k = 1:N
    F = sprintf('point%d',k);
    A = mystruct.(F);
    ... do whatever with A
end
https://www.mathworks.com/help/matlab/matlab_prog/generate-field-names-from-variables.html
Note that your code would be simpler and more efficient if you used a non-scalar structure (or even a cell array), rather than accessing lots of fieldnames dynamically:
https://www.mathworks.com/help/matlab/matlab_prog/access-multiple-elements-of-a-nonscalar-struct-array.html
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