How do I rename variables from workspace for multiple matfiles?

Hello there! I am trying renaming those variables, e.g., 'img' to 'img_ldct' and 'lab' to 'lab_ldct', and making these two matfiles' variable names become same.

img_ldct=img;
clear('img')

I have tried the above code and it worked, but the new variable name did not saved in matfiles,which meant when I clicked the workspace later, the variable name was still 'img', not 'img_ldct'. How can I change variable names correctly? Also, is it possible to rename multiple matfiles automatically with the same name-changing rule, e.g., adding '_ldct' after original variable names?

Please suggest and thank you for helping!

Answer 1

[Les Beckham]

clearvars
load('filename.mat') % load data that you want to change (replace filename with actual name of your file)
img_ldct=img;        % do the rename
clear('img')
save('matfile1.mat') % save the result with the change
% repeat for any other mat files that you want to make changes to 

[KuanTing Wu]

Thank you! I really appreciate your suggestion and it works! May I ask how should I use a loop to rename multiple matfiles automatically with the same name-changing rule, e.g., adding '_ldct' after original variable names?

Answer 2

[Rik]

With the syntax Les posted it is not possible to apply this to multiple mat files and variables automatically, which is one of the reasons to load to a struct instead. That way it is obvious where variables are coming from and you can use fieldnames to get all the variable names.

rename_variables('filename.mat','_ldct')

function rename_variables(filename,suffix)
Sin=load(filename);
Sout=struct;
fn=fieldnames(Sin);
for n=1:numel(fn)
    Sout.([fn{n} suffix])=Sin.(fn{n});
end
save(filename,'-struct','Sout')
end

I will leave it as an excersize to you to write comments and documentation for this function.

[KuanTing Wu]

Hello, sorry for the late reply. I have solved this problem in another way a few days ago, but still appreciate your suggestion!

[Stephen23]

+1 this is the best, robust, general approach.

[Belén]

There seems to be a typo, it should be:

fn=fieldnames(Sin);

[Rik]

Thank you for catching this. I have edited my answer.