How to save specific variable names

Hello!

I have a large workspace and i want to save workspace variables that includes specific characters and letters. For example i want to save multiple variables that contains "T22P50" in their name. For instance, I got the variable names "Pressure_T22P50", "Position_T22P50" etc and i want to save these into a .mat file. Since these variables changes for different tests (T22P50, T30P50 etc), is there a way that the save function can search in the workspace for variables containing the specific characters, instead of manually changing them each time?

I hope the question is clear, thanks in advance!

[Stephen23]

Note that your code would be much simpler, faster, and more reliable if you did not put meta-data into variable names:

https://www.mathworks.com/matlabcentral/answers/225435-save-variable-as-string-from-user-input

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Better code (simpler, faster, more reliable, easier to read,...) would simply use indexing or fieldnames instead of putting meta-data into variable names. Then your question would simply require saving one variable, and would not rely on ugly hack code.

Answer 1

[KL]

workspaceVars = who;
findVars = strfind(workspaceVars, 'P250');
indexVars = find(not(cellfun('isempty', findVars)));

Now you can use workspaceVars and indexVars along with save. For example,

save('name.mat',workspaceVars{indexVars(1)})

[abj9]

That is perfect, thank you!

I have an additional question. Is it possible to change whats inside the apostrophes (' ') several places at once (like shift+enter)? Now I have to change it manually each place.

Best regards!

[KL]

What do you mean? In the above code, 'P250' and 'isempty' both are between quotes but I don't think you'd wanna change 'isempty'.

[abj9]

I mean like in general. If i want to change "T22P50" several places in the script at once, when it is inside apostrophes.

For instance: addpath('.....\T22P50')

fopen('T22P50')

save('T22P50')

Is it possible to change whats inside the ' ' term just once, and the others will change accordingly, or do I have to change it manually each place?

[KL]

Intuitive idea is to define that as a variable and just change it just once at the top. If you have all the possible names in an array, even better.

[abj9]

Thank you, KL! Your answers helped me a lot :)

Answer 2

[Fangjun Jiang]

    Vars=who('*_T22P50');
    save('MatFile',Vars{:});