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MatLab doesn't read my .TXT file correct

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Peter Bu
Peter Bu on 20 Jul 2018
Commented: Noam Greenboim on 21 May 2020 at 21:29
Hello everyone,
i have an issue where my .TXT file is not readable my MatLab. I am not sure what to do. Can somebody please give me a hint? I can open it with other tools like "Atom".
Thanks in advance!

  2 Comments

Jeremy Hughes
Jeremy Hughes on 20 Jul 2018
It would help to see the actual file. My suspicion is that the file is encoded with something MATLAB doesn't expect, like UTF-16.
Peter Bu
Peter Bu on 20 Jul 2018
Oh yes. I missed to attach the file. Here it is :-)

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Accepted Answer

Jeremy Hughes
Jeremy Hughes on 20 Jul 2018
Thanks for uploading the file!
The first issue I see is that the file has a UTF-16 byte-order-mark. The file is stored as UTF-16 which isn't fully supported in MATLAB. This is why you see the extra boxes between each of the characters.
I did the following to check that your file even needed to be UTF-16--it doesn't.
fid = fopen('Charge4_Probe_3.txt','r','n')
bytes = fread(fid)';
fclose(fid);
bytes(1:20) % inspect a few of the bytes, you can see what's going on
bytes(1:2) = []; % remove the byte order mark
any(bytes(2:2:end) ~= 0) % every other byte is NULL
So none of the characters are using the second byte--effectively this is an ascii file. I'd look into the source of the file and see if you can get it as utf-8 (that will half the file size)
To get a new file, you can write as follows:
asciibytes = bytes(1:2:end) % strip out the zero bytes
fid = fopen('Charge4_Probe_3_ascii.txt','w','n','UTF-8');
fwrite(fid,asciibytes);
fclose(fid);
This is now ready to be read. (Note: as Aquatris mentions, these are using a decimal separator of comma.)
To read this programatically, you can do this:
opts = detectImportOptions('Charge4_Probe_3_ascii.txt','Delimiter','\t');
opts.DataLines = [4,inf];
opts = setvartype(opts,'double');
opts = setvaropts(opts,'DecimalSeparator',',');
T = readtable('Charge4_Probe_3_ascii.txt',opts);
head(T)
Hope this helps,
Jeremy

  2 Comments

Peter Bu
Peter Bu on 20 Jul 2018
Thanks a lot for your time and the detailed answer!
Noam Greenboim
Noam Greenboim on 21 May 2020 at 21:29
Here is an easy way to tell the encoding of your file:
Usage:
FileEncoding = BOM('Charge4_Probe_3.txt')
This uses the same idea as described above.

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More Answers (1)

Aquatris
Aquatris on 20 Jul 2018
Your data has comma (,) in them. I do not think Matlab can read values with commas, i.e., 2,230. You should change those commas to dots as in answered in another question in this forum .

  2 Comments

Aquatris
Aquatris on 20 Jul 2018
Also, I used Matlabs "import data" functionality and it was able to read the data correctly, just the variables with commas were NaN instead.
Peter Bu
Peter Bu on 20 Jul 2018
also thank you for your time and answer :-)

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