I have to concatenate 6 .mat eeg files

I have to concatenate six .mat files that contains EEG data. The data has 8 channels and different samples.

I want to concatenate the data column wise so that there are 8 rows for channels and the samples keep on adding column wise.

Answer 1

[Walter Roberson]

filenames = {'first.mat', 'second.mat', 'third.mat', 'fourth.mat', 'fifth.mat', 'sixth.mat'};
nfiles = length(filenames);
data_cell = cell(nfiles,1);
for K = 1 : nfiles
    data_struct = load(filenames{K});
    %we do not know the names of the variable the data is stored in. 
    %assume it is the first variable in the file.
    fn = fieldnames(data_struct);
    this_data = data_struct.(fn{1});
    data_cell{K} = this_data;
end
%now put it all together into one matrix
data = vertcat(data_cell{:}) .';

[Harshini Gangapuram]

I have tried this code. But it gives me error. This EEG data gives me trouble all the time.

[Walter Roberson]

What error message does it give?

What are the variable names stored in the files? What are the sizes of the stored variables?

[Harshini Gangapuram]

The files were not of same size. Now I resized them and concatenated. Now I want to save the concatenated file. Below is the error I got.

>> save(data)

Error using save

Must be a string scalar or character vector.

>> save(data.mat)

Dot indexing is not supported for variables of this type.

>> save('Concatenate.mat',data)

Error using save

Must be a string scalar or character vector.

[Walter Roberson]

save('Concatenate.mat', 'data')

or

save Concatenate.mat data

[Harshini Gangapuram]

Got it. Thank you!!!!