Reading Multiple CSV Files in a Sequence

I wrote a code to read and process 55 csv files.

The first step was to read the data and save it in a cell structure in away that each csv file would be saved in a cell a table:

d=dir('*.csv');                  % list all csv files in working directory
n = length(d);                   % number of files in the directory
tempdata=cell(1,n);              % preallocate a cell array to hold results

for i=1:n
    tempdata{i}=readtable(d(i).name);    % read each file
end

I expected that the 1st. csv file will be stored in tempdata{1,1}, 2nd in cell tempdata{1,2}, etc.. but I noticed that:

tempdata{1,1} = file1.csv

tempdata{1,2} = file10.csv

tempdata{1,3} = file11.csv

.

.

tempdata{1,12} = file2.csv

.

.

How can I change the sequence of saved files so:

tempdata{1,1} = file1.csv

tempdata{1,2} = file2.csv

tempdata{1,3} = file3.csv

.

.

tempdata{1,10} = file10.csv

.

.

tempdata{1,55} = file55.scv

Appreciate the time and efforts that you put to answer this question.

Answer 1

[Mathieu NOE]

hello

that's the Achille heel of the native dir command

it will not sort the file names correctly

you need this : Natural-Order Filename Sort - File Exchange - MATLAB Central (mathworks.com)

my example below :

%% read multiple files 
P = pwd; % currrent directory

S = dir(fullfile(P,'*.csv')); % get list of files in directory
S = natsortfiles(S); % sort folders / file names into order (https://fr.mathworks.com/matlabcentral/fileexchange/47434-natural-order-filename-sort)

for k = 1:numel(S);
    F = fullfile(P, fileNames_sorted{k});
    S(k).data = csvimport(F); % or READTABLE or whatever.
end
% Take a look in the structure S: it contains all of your file data and the corresponding filenames, just as you require.
% For example, the 2nd filename and its data:
S(2).name
S(2).data
% Accessing and processing this will be much simpler than messing around with dynamically named variables.

[Usama Al-Saffar]

Thank you Mathieu for the prompt answer. It looks logical to me but Matlab doesn't recognize the natsortfiles function!

[Usama Al-Saffar]

OK. I just realized that I need to download this function first since it is not a standard function in Matlab.

[Stephen23]

"It looks logical to me but Matlab doesn't recognize the natsortfiles function! "

You need to download the function. File Exchange is a forum for third-party code that is not part of MATLAB.

Open the link that Mathieu NOE gave you. Click on the big blue Download button in the top right corner. Save the ZIP file on your computer. Unzip the zip file into the current MATLAB directory (or on the MATLAB path).

[Usama Al-Saffar]

Thank you Stephen. I already figure that out and downloaded the function.