How do I read and plot ".trc" file?

Hi every body,

I have a ".trc" file (C3--Trace--00001.trc) thi is the output of the BER tester, now I wont to read and plot this file in Matlab.

can you help me?

[Rik]

It looks like there is a function that does this on the FEX. Did you try it? Did you get any errors?

[Paolo Mirabelli]

I do not understand you. what is FEX?

I have tried the solution posted in this topic " How do I view .trc files?" but it doesn't work. I have an error with function

readtrace('C3--Trace--00001.trc'); Unrecognized function or variable 'readtrace'.

at this point i don't know ho to proceed.

can you help me?

can you suggest me some library for loading a trc file and the plot?

thank you very much

[Rik]

The FEX is the FileExchange. I this case I was referring to this function.

Functions posted on the FileExchange are written by cummunity members. You can either download the files from the website, or (only if you have R2017a or later) you can use the AddOn-manager. Otherwise Matlab can't find the function.

[Paolo Mirabelli]

thank you very much, I have installed readtrc from FileExchange but now i have this error:

>> readtrc('C3--Trace--00001.trc');
Array indices must be positive integers or logical values.
Error in readtrc (line 20)
traces{k+1,1}=cell2mat(Columns(TracesIdx(size(TracesIdx))+4:size(Rows{1,1})));

[Rik]

I suspect TracesIdx is empty. The function is also written a bit strangly, by using size without specifying the dimension, while treating the output as a scalar.

Since it is a function from December 2014 and the author did not reply to a comment in November 2017, I doubt posting a comment will do much.

This function itself suggests a trc file is (mostly?) plain text. That means you can use normal text file reading tools to parse the file yourself.

[Jan]

Please provide an input file, such that we can reproduce the problem. The best point to start from is contacting the author of the FEX submission, because he or she knows the code very well.

[Paolo Mirabelli]

I tried to attach but it is larger than 5MB(also .zip).

what function would you suggest me to read the file and have frequency and data in an array?

load() return this erro:

Error using load
Unknown text on line number 1 of ASCII file C3--Trace--00001.trc
"#9500000348WAVEDESC".

• I guess I should read the file

    data=readMyTrcFile('C3--Trace--00001.trc')

• read frequency

 f=data(:,1)

• read Amplitude

     d=data(:,2)

and after plot(f,d), but how i can read this file? load doesn't work

fileread return an array "1x500000359 char" but in this case i don't have f and data. How can i proceed?

[Rik]

You have a text file. Have you opened it with something like Notepad to look at the contents?

You haven't read the documentation for either the load function or the fileread function. I would suggest you read the documentation of any function you try to use, especially if you get an error.

If you want to read your file line by line, you can use my readfile function (which you can get from the FEX, or if you are using R2017a or later, you can also get it through the AddOn-manager). If you are using R2020b, you can also use the readlines function. Then you can write code that will extract the data from that line in your file.

I doubt you need to post all 500 million characters of the text file to show what is in your file and what you want to extract.

[Paolo Mirabelli]

Hi @Rik, thanks for the time you are dedicating to me.

I have tried to open the file with notepad and this is the result:

this is the first time that I find myself reading such files. thi file is the output of the BER(Bit Error Rate) Tester.

[Rik]

I don't think I have seen something like this before. My only guess is that the file is too large for Notepad++ to properly load the file.

What you could do is attach the file you get if you do this:

chr=fileread('C3--Trace--00001.trc');
fid=fopen('C3--Trace--00001_part1.txt','w');
fprintf('%s',chr(1:10000));
fclose(fid);

That should be small enough to attach.

[Paolo Mirabelli]

hi Rik,

I have attached the file txt obtained with your script.

[Rik]

Well that at least answers the question why the FEX submission I linked doesn't work: it is a completely different format.

Do you have any documentation about this file? What program should be used to read such a file?

[Paolo Mirabelli]

unfortunately no, I write them here on the post

[Walter Roberson]

@Paolo Mirabelli

Your .trc file is LECROY_2_3 format. You should get ReadLeCroyBinaryWav​eform by Jean-Daniel Deschênes from the File Exchange.

Answer 1

[Shubham Khatri]

Hello,

Please go through this MATLAB Answer.

Hope it helps