MATLAB: Loading multiple .mat files by using for loop

for looploadmatMATLAB

Hello, I am trying to load some .mat files and run some specific commands on. The .mat files are named as the following:
 % Data Files
dataset1_1.mat     dataset2_1.mat     dataset3_1.mat     ...and so on
dataset1_2.mat     dataset2_2.mat     ...and so on
dataset1_3.mat     ...and so on 
...and so on
I want to first load all the dataset1_*.mat files and then perform some calculations on each of them in order (i.e. perform calculations on dataset1_1.mat, then dataset1_2.mat…and so on).
After completing all of the dataset1_*.mat files, I would like to move onto the next batch of files, dataset2_*.mat, and repeat(i.e. perform calculations on dataset2_1.mat, then dataset2_2.mat…and so on).
Process will continue until the last dataset*_*.mat file.
Here is my code so far
% code
files = dir('dataset*_1.mat');
for i = length(files)
  files2 = dir('dataset(i)_*.mat');
  for j = 1:length(files2)
      a = load(files2(j).name);
        %Perform some calculations on dataset
    end
end
I am using 2 for loops, not sure where I am going wrong. Thanks for the help!

Best Answer

the line
_files = dir('dataset*_1.mat');_
returns dataset1_1, dataset2_1,... not what you want. then
files2 = dir('dataset(i)_*.mat')
will return nothing, because (i) is not interpreted, you're asking for a file exactly named 'dataset(i)_*.mat'.
you should do something like
% number of set (dataset1, dataset2, ...if unknown, figure it out).
NumberOfDataset = 3;
for i = 1:NumberOfDataset 
    % get allfiles matching the pattern 'dataset(i)_*'
    files = dir(sprintf('dataset%d_*.mat',i));
    for j = 1:length(files)
        fprintf('Current file : %s\n',files(j).name)
        a = load(files(j).name);
        %Perform some calculations on dataset
    end
end
Related Question