I want to loop for files in workspace

7 views (last 30 days)
Chuchu Debebe
Chuchu Debebe on 12 May 2022
Commented: Chuchu Debebe on 13 May 2022
Dear all,
I have a lot of data that I imported into my workspace. Let's say I have data1, data2,... and dataN in my workspace. For example, I want to get length(data1), length(data2),... and length(dataN) automatically using a loop. Do I have any way to do that?
  1 Comment
Stephen23
Stephen23 on 12 May 2022
"Let's say I have data1, data2,... and dataN in my workspace."
And that is the start of your problems: badly-designed data with pseudo-indices forced into the variable names. Accessing numbered variable names in a loop is one way that beginners force themselves into writing slow, complex, inefficient, buggy code that is difficult to debug:
Much better data design would use one array, then you could use simple and efficient indexing, just like MATLAB is designed for.

Sign in to comment.

Accepted Answer

Stephen23
Stephen23 on 12 May 2022
"Let's say I have data1, data2,... and dataN in my workspace."
Lets assume that you did not name them all by hand, but instead that you LOADed them one-by-one from some MAT files. In which case, that is the correct place to fix the badly-designed data, e.g. renaming the variable in each MAT file to use exactly the same name, which would make it much easier to write simple, efficient, robust code to process your data.
Remember to always LOAD into an output variable!
If you cannot rename the MAT file vairiables and there is exactly one variable per MAT file, then we can LOAD them like this to avoid having lots of ugly numbered variable names in the workspace:
P = 'absolute or relative path to where the files are saved';
S = dir(fullfile(P,'*.mat'));
N = numel(S);
C = cell(1,N);
for k = 1:N
F = fullfile(P,S(k).name);
C(k) = struct2cell(load(F));
end
V = cellfun(@numel,C)
Simpler and much more efficient than trying to mess around with dynamic variable names.
  7 Comments

Sign in to comment.

More Answers (1)

KSSV
KSSV on 12 May 2022
s = whos ;
for i = 1:length(s)
s(i).size
end

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!