Hi
The file = files' statement is quite crucial, but should be correct like this. The foor loop (by default) will loop through the first row, that's why you need to transpose it to files'. Personally, I would rather do something like
files = dir('*.csv');
N_files = length(files);
for idx = 1:N_files
...
end
so that the orientation of files doesn't matter, but other people would probably do it differently.
To your issue: In each iteration, you are overwriting the value of Error... so in the end, Error will have one value, namely the one from the last file. If you want the error value for all files, you need to create a vector Error of length N_files, and then set each element i to the error from the corresponding file i.
I.e. something like
files = dir('*.csv');
N_files = length(files);
Error_Vector = zeros(N_files,1);
for idx = 1:N_files
%%load and process files
filename = fopen(files(idx).name);
% ... etc
Error_Vector(idx) = abs(Input_grad - Grad);
fclose(filename);
end
