Is it possible to extract all fields from a structure automatically?

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Mr M.
Mr M. on 10 Aug 2016
Commented: Ludmila Kuncheva on 24 Aug 2021
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!)
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Accepted Answer

Stephen23
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')
and then load it like this:
>> clear
>> load('temp.mat')
>> name
name = anna
>> data
data =
1 2 3
and you will find all of those variables in your workspace.

More Answers (2)

Baium
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
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Azzi Abdelmalek
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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