Extracting specific rows from multiple data files to store as variables

I'm very new to Matlab.

I have multiple data files (file type file) of dimensions 5x12001, each representing data from an experiment.

For each file I want to extract the first two rows (i.e. to have a 2x12001 matrix from each file (or two 1x matrices)) and store in such a way that allows me to keep track of which stems from which file.

I've tried generating a cell array:

files = dir('*.');
files = files(~ismember({files.name},{'.', '..'})); %gets rid of empty files invisible in explorer

for i = 1:length(files)
    C{i} = load(files(i).name);
end

But I'm not sure how to efficiently manipulate the matrices once indexed in a cell array.

This crappy function sort of represents what I'm trying to achieve:

function [wavelength, datavalue] = getmatrix(filename)

matrix = readmatrix(filename);
wavelength = matrix(1,:);
datavalue = matrix(2,:); 

end

But I'd like to be able to loop through all the files without having to manually call the function on each filename.

Thanks, and sorry for my staggering ineptitude.

Answer 1

[Stephen23]

"....and store in such a way that allows me to keep track of which stems from which file."

That is easy using the structure returned by dir:

S = dir('*.csv'); % better to specify the file extension!
for k = 1:numel(S)
    tmp = load(S(k).name); % you should probably use DLMREAD or similar.
    S(k).data = tmp(1:2,:) % 1st & 2nd rows.
    % OR
    S(k).wavelength = tmp(1,:); % 1st row.
    S(k).datavalue  = tmp(2,:); % 2nd row.
end

https://www.mathworks.com/help/matlab/matlab_prog/comma-separated-lists.html

https://www.mathworks.com/matlabcentral/answers/320713-how-to-operate-on-comma-separated-lists

[Alexander Collins]

That's great Stephen, thanks!

I was initially confused how to reference the actual data in the structure array (as linked in the top-left cell of the attached picture), but I realised I can just refer to is as, for example, S(1).data(1,:) (for the first row of the first file in structure S).