CODEWITHSUNDEEP
matlabmatrixfile-readdirectory-listingmat-file
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Reputation: 25

Loading multiple .mat files into a matrix and performing operations on it

I have 429 numerical matrices of identical size (107 rows by 36 columns), stored inside sequentially named .mat files (e.g: subj_00000.mat ... subj_00428.mat). Here's what I need to do:

  1. Import into the MATLAB workspace.
  2. After importing, average all of them to generate another matrix, which will also have a dimension of 107x36.
  3. Finally, linearly correlate each column of the average matrix with each column of each of the original 429 matrices, to generate a new matrix of 429 rows and 36 columns.

So far I got to the stage of building a 107 x 36 x 429 array to be filled with my set of matrices.

S = dir(fullfile(D,'subj*.mat')); % D is the path where the .mat files are saved
N = numel(S);
C = cell(1,N); % preallocate cell array
for k = 1:N
    S = load(fullfile(D,S(k).name));
    C(k) = struct2cell(S);
end
A = cat(3,C{:}); % join all of the original matrices into a 107x36x429 array
M = mean(A,3)

but I get the following error message: 

Reference to non-existent field 'name'.
Error in myscript (line 6)
S = load(fullfile(D,S(k).name));

Upvotes: 1

Views: 252

Answers (1)

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Connectome

Reputation: 25

You are looping over S yet overwriting it every time. Rename the S that is inside the loop. While you are at it I would give all your variables meaningful names--there is no need to use a single letter every time. – svdc

Thank you! I renamed 

S = load(fullfile(D,S(k).name));

as 

T = load(fullfile(D,S(k).name));

and it worked

Upvotes: 0

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