How can I combine multiple matfile containing row vector in one table

I have several dot matfile containing row vector and I want them to put in one table sequentially (according to alphabetic order of the file name).

I tried the following script which I found in Math works, it combines all the files in one table, however when I use it for more number files it do not work sequentially and I faced difficulty to identify which row corresponds to which file.

clear

FileList = dir('As*.mat');

DataC = cell(1, numel(FileList));

for iFile = 1:numel(FileList)

FileData = load(FileList(iFile).name);

DataC{iFile} = FileData.X;

end

DataM = cat(1, DataC{:});

I have attached sample dot mat files

Thank You for response

[Nikhil Sapre]

Hi Yared,

Can you check if the order is correct in the variable FileList. My guess is the problem happens because the sorted order would be As(1), As(10), As(2) etc .. when using the dir function

A workaround would be to name your file As(01), As(02), As(03) and so on. This should fix the order.

Thanks,

Nikhil

[Yared Daniel]

Thank you so much, Nikhil. Now I understand the problem, but I have thousands of files and renaming them manually is a kind of tiresome. is there any means to rename all the files once?

[Nikhil Sapre]

You don't need to rename the files. You can sort it based on date created. Here's a snippet of code how to do this in your case. This is assuming your files were created in the order they are named.

FileList = dir('As*.mat');
DataC    = cell(1, numel(FileList));
[~,idx] = sort([FileList.datenum]);
for iFile = 1:numel(idx)
  FileData     = load(FileList(idx(iFile)).name);
  DataC{iFile} = FileData.X;
end
DataM = cat(1, DataC{:}); 

[Yared Daniel]

Thank you again

[Nikhil Sapre]

Done, thanks

[Stephen23]

A more robust solution that does not assume that the files were created/modified in the filename order:

https://www.mathworks.com/matlabcentral/fileexchange/47434-natural-order-filename-sort

For example:

P = 'absolute or relative path to where the files are saved';
S = dir(fullfile(P,'As*.mat'));
S = natsortfiles(S);
for k = 1:numel(S)
    F = fullfile(P,S(k).name);
    D = load(F);
    S(k).X = D.X;
end
DataM = cat(1, S.X); 

[Nikhil Sapre]

Thanks. This is a better solution. I didn't know of the natsortfile function.

Answer 1

[Nikhil Sapre]

Hi Yared,

Can you check if the order is correct in the variable FileList. My guess is the problem happens because the sorted order would be As(1), As(10), As(2) etc .. when using the dir function

A workaround would be to sort it based on date created. This code should fix it, assuming your files were created in the order they are named. .

FileList = dir('As*.mat');
DataC    = cell(1, numel(FileList));
[~,idx] = sort([FileList.datenum]);
for iFile = 1:numel(idx)
  FileData     = load(FileList(idx(iFile)).name);
  DataC{iFile} = FileData.X;
end
DataM = cat(1, DataC{:});