Load data with varying names

I have data files (.mat format) which consists of 140 files which only vary in their name which a increasing number:

cam_0_C182_0000001.mat

cam_0_C182_0000002.mat

...

cam_0_C182_0000140.mat

From those files (which are matlab structures, and i am intrested in a single value from a matrix within that structure.

How can i construct a loop which automatically loads all the files, and gets that one value, and places them in a new array?

for i = 1:140
    Structure = cam_0_C182_0000('i').mat;
    Output(i) = Structure.X(6,73); % get value (6,73) from matrix X, within the structure
end

My problem mainly is that i am not sure how to convert the numbers i from the loop to string value for the .m files in the folder, furthermore does 1 have to be translated to string (001), 45 to (045) and 101 to (101), so how do i format this number correctly to place zeros in front of the number if lover then 10, or then 100?

Thanks in advance

[Stephen23]

Your description is unclear: "I have data files (.m format) which consists of 140 files which only vary in their name which a increasing number: cam_0_C182_0000001.mat...". So what do you actually have saved in that folder:

• M-files (.m, as you wrote in your description) which are text files containing code.
• Mat files (.mat, as your examples show) which are binary files containing data.

Mixing things up makes it hard for us to know what you are actually doing.

Answer 1

[Stephen23]

The MATLAB documentation explains how:

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

The easy approach is to use DIR:

P = 'absolute or relative path to where the files are saved':
S = dir(fullfile(P,'cam_0_C182_0*.mat'));
N = numel(S);
V = nan(1,N);
for k = 1:N
    D = load(fullfile(P,S(k).name));
    V(k) = D.X(6,73);
end

Else use SPRINTF if you really want to generate the filenames from numerics:

N = 140;
V = nan(1,N);
for k = 1:N;
    F = sprintf('cam_0_C182_%07d.mat',k);
    D = load(fullfile(P,F));
    V(k) = D.X(6,73);
end

In both cases you will need to LOAD the filedata (the syntax you show in your question does not exist).

[Jeroen van Bemmel]

Thank you so much!

much less code then i was anticipating.

you are the mvp ;)