Removing loaded variables from workspace after changing name with eval

Hi,

I have a large data set, where each filename goes as XX001 etc. each filename is also the name of the stuct in the workspace.

so i use eval to rename it:

DataFiles = dir('C:\MyFolderPath'); 
    
for i = 1:length(DataFiles)
    SubjectName = DataFiles(i).name;       
    load(SubjectName); eval(['patient', ' = ', SubjectName, ';'])
end

since i want my code to fit all the data, i change the names.

but then, i'm left with the original file name in the workspace.

how can i delete it?

Thank you!

[Stephen23]

"how can i delete it?"

By avoiding this situation entirely and NOT using awful anti-pattern eval.

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

Answer 1

[Stephen23]

Do NOT use eval for such trivial tasks as importing data.

Either access the fieldname, e.g.

S = dir('C:\MyFolderPath');
N = numel(S);
for k = 1:N
    F = S(k).name;       
    T = load(F);
    patient = T.(F);
end

Or use a cell array (this assumes exactly one variable per mat file):

for k = 1:N
    F = S(k).name;       
    C = struct2cell(load(F));
    patient = C{1};
end

See also:

https://www.mathworks.com/help/matlab/import_export/process-a-sequence-of-files.html

Answer 2

[Fangjun Jiang]

Use one example, figure out if you can use the code below. If not, use "clear" to delete variable from workspace.

Patient=load(SubjectName);
Patient=Patient.(SubjectName);