How to load all .mat file in the current directory and save them as .wav file?

Hello everyone,

I want to load all '.mat' files from a folder. All these '.mat' files have two vectors names 'right' and 'left'. I want to save these two vectors as two separate '.wav' files. Here is the code that I used to do it:

clear 
close all
clc

%% reading all the files in the current directory
path_directory = 'C:\Users\Desktop\BE';
original_files=dir([path_directory '/*.mat']);


%% loading each file and save them as a wav file

for k=1:length(original_files)
    filename=[path_directory '/' original_files(k).name];
    load(filename)
    wavname_r = filename + '_r.wav';
    fs = FS_AUDIO;
    sig_r = right;
    audiowrite(wavname_r,sig_r,fs);
    wavname_l = filename + '_l.wav';
    sig_l = left;
    audiowrite(wavname_l,sig_l,fs)
end

But it didn't work well and I got this error:

Arrays have incompatible sizes for this operation.

Error in mat_to_wav (line 15)

wavname_r = filename + '.wav';

could you please explain to me how to solve it??

Thank you very much in advance.

[Stephen23]

"could you please explain to me how to solve it??"

Do not use + on character vectors (unless you really want to add the character codes of compatibly-sized char vectors).

The + operator is overloaded to operate on string arrays, as its documentation explains:

https://www.mathworks.com/help/matlab/ref/plus.html#mw_cb32e46d-7898-49de-b2a8-36bc9eea8f3f

Answer 1

[Stephen23]

P = 'C:\Users\Desktop\BE';
S = dir(fullfile(P,'*.mat'));
for k = 1:numel(S)
    F = fullfile(S(k).folder,S(k).name);
    D = load(F);
    [~,N] = fileparts(S(k).name);
    FnL = fullfile('.',sprintf('%s_l.wav',N));
    audiowrite(FnL, D.left, D.FS_AUDIO);
    FnR = fullfile('.',sprintf('%s_r.wav',N));
    audiowrite(FnR, D.right, D.FS_AUDIO);
end

[Malahat Hajkarimi Mehrban]

Thank you very much, it works well.