Brace indexing is not supported for variables of this type.

I am getting the following error for the attached code.

Error in Readfiles (line 8)

data = readmatrix(fnames{idx});

Could you please help me out.

Answer 1

[Ameer Hamza]

fname is a struct, not a cell array. Change the line to

data = readmatrix(fnames(idx).name);

[Sateesh Kandukuri]

Dear Ameer Hamza, Thank you so much for the quick reply.

[Ameer Hamza]

I am glad to be of help!

[Sateesh Kandukuri]

Dear Ameer Hamza, the previous programme didn't read the .csv files in an order. I used 'natsortfiles' function to read them in proper order. But I am getting an error.

Dot indexing is not supported for variables of this type.

Error in Readfiles (line 11)

data = readmatrix(fnames(idx).name);

[Ameer Hamza]

This code does not contain natsort. How did you sorted the struct array 'fnames'?

[Sateesh Kandukuri]

Please go through the second time attached code.

[Ameer Hamza]

Yes, I am referring to the file attached in your comment. It does not have a call to natsortfiles().

[Sateesh Kandukuri]

I am really sorry, I have attached a wrong file previously. Here is the right file.

[Ameer Hamza]

This code does not contain the line

data = readmatrix(fnames(idx).name);

as shown in your previous comment. In any case, N is a cell array in your case and you can acess the filenames like this

data = readmatrix(N{idx});

[Sateesh Kandukuri]

Thanks for your time. I resolved the problem.

Answer 2

[KSSV]

% List all CSV files
fnames = dir('*.csv');
% Pre-allocate output vector
ranges = zeros(numel(fnames), 1);
% Loop over file names
for idx = 1:numel(fnames)
    % Read the CSV data
    data = readmatrix(fnames(idx).name);
    % Get the 5th column
    col5 = data(:,5);
    % Get the range for this file
    ranges(idx) = max(col5) - min(col5);
end
% Write the result
writematrix(ranges, 'ranges.csv');

[Sateesh Kandukuri]

Dear KSSV, Thank you so much for the quick help.