Is it possible to extract all fields from a structure automatically?
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I have data in the form: mydata.x = 100; mydata.s = 'abc'; mydata.Y = [1 2 3]; And I want variables x = 100; s = 'abc'; Y = [1 2 3]; How to extract variables automatically? (suppose that I don't know the names of the variables!)
7 Comments
Stephen23
on 14 Nov 2019
Edited: Stephen23
on 14 Nov 2019
"Why anybody think that this is a dynamic variable in my example?"
Because that is exactly what load does, when called without an output argument: it dynamically creates all of the loaded variables in the caller workspace:
https://www.mathworks.com/matlabcentral/answers/335253-mat-files-not-loading-correctly#answer_262994
And of course:
Accepted Answer
Stephen23
on 11 Aug 2016
Edited: Stephen23
on 11 Aug 2016
You seem intent on magically making variables pop into existence in the workspace, so here is probably the least-worst way of doing that. The trick is to change the save command by adding the '-struct' option:
>> S.name = 'anna';
>> S.data = 1:3;
>> save('temp.mat','-struct','S')
>> clear
>> load('temp.mat')
>> name
name = anna
>> data
data =
1 2 3
and you will find all of those variables in your workspace.
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More Answers (3)
Baium
on 14 Nov 2019
Edited: Baium
on 14 Nov 2019
Alternative, maybe this is more desired than dictating how the struct will be saved in the workspace (this will recursively unpack any struct within the struct):
function unpackStruct (structure)
fn = fieldnames(structure);
for i = 1:numel(fn)
fni = string(fn(i));
field = structure.(fni);
if (isstruct(field))
unpackStruct(field);
continue;
end
assignin('base', fni, field);
end
end
6 Comments
Alec Jacobson
on 9 May 2021
Or as a single anonymous function (which you can drop into your ide)
unpackStruct = @(s) cellfun(@(name) assignin('base',name,getfield(s,name)),fieldnames(s));
Azzi Abdelmalek
on 10 Aug 2016
Edited: Azzi Abdelmalek
on 10 Aug 2016
Use fieldnames function
mydata.x = 100;
mydata.s = 'abc';
mydata.Y = [1 2 3];
field=fieldnames(mydata)
Then you want to assign to each variable individually a corresponding value, which is not recommended. Read this http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F
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