How can I import multiple files into the MATLAB workspace?

I have a set of about 50 data files which I want to import to MATLAB. Each file has several columns.

I have found that the command

load -ascii  filename.txt

works rather well for my purpose on a single file. However, I want to load about 50 different files. I would like some direction on how best to load multilple files into separate arrays.

Answer 1

[MathWorks Support Team]

You can use the "load" function in a loop to load in all the files. If you place all of the files you would like to load into a single directory, you can use the "dir" function to capture the file names. Here is an example:

files = dir('*.txt');

for i=1:length(files)
    load(files(i).name, '-ascii');
end

This code will load in all of the files in the directory (assuming they are .txt files) and save them as arrays with the file name as the array name.

Other functions that might be more suitable for your application include "importdata, "textscan", "dlmread" and "readtable".

For more information on importing data into MATLAB refer to the following URL:

https://www.mathworks.com/help/matlab/data-import-and-export.html

One more way of importing multiple files is using "Import Tool". The following documentation page provides steps required to generate the function and call the same using a MATLAB script.

https://www.mathworks.com/help/matlab/import_export/import-data-interactively.html

[Stephen23]

Note: This reply was in response to a previous answer and it's content has been integrated into the answer above (reply is from February 2021 and the answer above was updated in March 2021).

-----

Note that this code is unnecessarily complex because it relies on eval to indirectly call load using command syntax. Unfortunately @MathWorks Support Team does not know how to use simpler function syntax:

A = load(files(i).name,'-ascii')

All MATLAB beginners need to learn the difference, otherwise they will write obfuscated code like this answer.

https://www.mathworks.com/help/matlab/matlab_prog/command-vs-function-syntax.html

@nuvolet: your question is answered here:

https://www.mathworks.com/help/matlab/import_export/process-a-sequence-of-files.html