Rename a struct with a fieldname of another struct

Hi, I want to load a struct and the name of the struct is for example 'abc' and after that i want to load some fields of the struct like

data_array(1) = abc.data_1

data_array(2) = abc.data_2

but now my problem is that the struct isn't allways called abc...

so i want to use the name of the struct however it's called to load data_1 and data_2 in this case

[Stephen23]

"but now my problem is that the struct isn't allways called abc..."

And that is the cause of your difficulties, which will force you into writing slow, complex, inefficient code just to access your data: https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

You forgot to tell us the most important information: how did you get all of these differently-named structures into the workspace? For example, if you LOADed them, then you can avoid the issue by LOADing into an output variable:

S = load(..)

[Jan]

Yes, with S = load(...)

Answer 1

[Robert U]

Hi Jan,

it is good practice to load external data into a structure array such that the variable name is connected to the actual function/script whereas the top fieldname is the name of the saved struct. Then, you can use fieldnames()-command to retrieve the name of the loaded struct and continue work on that.

inputStruct = load(myFilename)              % load file
fieldsInputStruct = fieldnames(inputStruct) % retrieve the name of the saved struct

inputStruct.(fieldsInputStruct{1})          % use dynamic expressions to address the fieldnames

See for more information:

• https://de.mathworks.com/help/matlab/matlab_prog/generate-field-names-from-variables.html
• https://de.mathworks.com/help/matlab/ref/load.html?s_tid=doc_ta#d123e846287
• https://de.mathworks.com/help/matlab/ref/fieldnames.html?s_tid=doc_ta

Kind regards,

Robert

[Jan]

Thank you, its a very nice solution!

[Stephen23]

Assuming only one variable per MAT file:

C = struct2cell(load(..))
M = C{1}