Save each pair in container.Map to separate variable in .mat file
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Hi I Have a container.Map object in which I need each key, value pair to be saved to a variable within a mat file.
Was originaly doing this with eval but then discovered assignin. Is there a better way to do this?
I need the outputted mat file to contain individual variables and so can't just use list due to the application this .mat file will be used in.
Simplified code snippet below
M = container.Map();
M("var1") = [1 2 3];
M("var2") = [4 5 6];
saveVars = {};
for key = M.keys()
assignin('base', key, M(key))
saveVars(end+1) = key
end
save("output.mat", saveVars{:})
2 Comments
Stephen23
on 1 Feb 2021
Edited: Stephen23
on 1 Feb 2021
"Was originaly doing this with eval but then discovered assignin."
Replacing eval with assignin does not avoid any of the problems of dynamic variable names, in fact you just add extra obfuscation and latent bugs to the process (i.e. as well as having all of the disadvantages of using eval).
Accepted Answer
Stephen23
on 1 Feb 2021
Edited: Stephen23
on 1 Feb 2021
"Is there a better way to do this?"
Of course, just use the -struct option when calling save. Note that conversion to structure relies on the keys being valid fieldnames, which we already know they must be because you are anyway using them as variable names.
M = containers.Map();
M("var1") = [1,2,3];
M("var2") = [4,5,6];
% convert to struct:
C = [keys(M);values(M)];
S = struct(C{:});
save('myfile.mat','-struct','S')
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