Reading multiple txt files and placing numerical data in a matrix

Hi all, I'm trying to read multiple file text without the header and pile up their numerical content. I have attached an example txt file.

Here is the basic code I use:

[filename,pathname,d]=uigetfile('*.txt','MultiSelect','on');

filepath=fullpath(pathname,filename);

a=readtable(filepath);

a=table2array(a);

It works for 1 fIle but gives an error for more files selected. And then once I imported correctly multiple files, how do I pile their numerical content? I guess have to insert that in a for cycle. Bear in mind that different files can have different number of columns and rows.

Thanks in advance to anyone who will help me

[Chris]

If files can have different numbers of columns and rows, what sort of "pile" are you expecting? How would the data be related?

[Mathieu NOE]

hello

maybe it would be helful to share some text files so we can help you better

tx

[Jan]

"but gives an error for more files selected" - whenever you mention an error in the forum, attach a copy of the complete error message instead of letting the readers guess, what you can see already.

[Jeremy Hughes]

a = readtable(filepath);

a = table2array(a);

Should be equivalent to:

a = readmatrix(filepath)

Answer 1

[Jan]

See: FAQ: How can I process a sequence of files?

[filename, pathname] = uigetfile('*.txt','MultiSelect','on');
filename = cellstr(filename);
data = [];
for k = 1:numel(filename)
  filepath = fullpath(pathname,filename);
  tab      = readtable(filepath);
  data     = cat(1, data, table2array(tab));
end

[Iacopo]

Thanks for your help Jan,

it returns this error msg:

unrecognized function or variable "fullpath".

error in:

filepath = fullpath(pathname,filename);

do you know why? thanks for your help

[Mathieu NOE]

Which matlab release are you running ?

[Iacopo]

Hi Mathieu,

MATLAB R2022a, but trial release until my purchase is completed. Thanks

[Jan]

@lacopo: I've copied "fullpath" from your example in the question. Maybe "fullfile" is meant.

[Iacopo]

@Jan you're right, my bad. I modified the piece of code but it doesn't work for more than 1 file. I changed the class of filepath to string to make the readtable function work:

[filename, pathname] = uigetfile('*.txt','MultiSelect','on');

filename = cellstr(filename);

data = [];

for k = 1:numel(filename)

filepath = string(fullfile(pathname,filename));

tab = readtable(filepath);

data = cat(1, data, table2array(tab));

end

If I select 2 files (I just created a copy of my file and selected both the original and the copy) and it gives me the following error:

Error using readtable

"filename" must be a string scalar or character vector.

Error in..

tab = readtable(filepath);