How do I view .trc files?

Hi. It's been a while since I've used matlab. I have some graphs in .trc files and I've been given a function that is supposed to be able to plot these files, but I'm having a hard time figuring out how it's done. Here's the function:

https://pastebin.com/CDvk2GK4

[Walter Roberson]

Code is:

function ExamplePlotImpedances(code,no)
% function ExamplePlotImpedances(src)
%
% Example program
% Load and plot a group of impedance measurements from HP8753, 
% saved as S11-parameters
% From functions written in LabVIEW at HBV-IMST

Zref = 50;                             % Ohm   Reference impedance

%-- Build fileames --
Nf = length(no);
for k=1:Nf
    src{k}= sprintf('%s%04d.trc', code, no(k));
end

for k=1:Nf
    %--- Load raw data ---    
    trc(k)= readtrace(src{k});

      %--- Create frequency vector, calculate Z, and plot impedance  ---
      f{k}= [0:trc.Np-1]*trc.dx+trc.x0;      % Hz   Frequency vector
  end

      S11{k} = double(trc.y(:,1)+ 1i*trc.y(:,2));
      Z = Zref* (1+S11{k})./(1-S11{k});         % Ohm  Complex impdance
  end
  keyboard
  subplot(2,2,1)
  semilogy(f,abs(Z));
  xlabel('Frequency [Hz]')
  ylabel('Impedance magnitude [Ohm]')
  grid on

subplot(2,2,3)
phi = angle(Z);
plot(f,rad2deg(phi));
xlabel('Frequency [Hz]')
ylabel('Phase [deg]')
ylim([-90 90])
set(gca, 'ytick', [-90:30:90])
grid on

subplot(2,2,2)
plot(f, real(Z), 'b-', f, imag(Z), 'r-');
xlabel('Frequency [Hz]')
ylabel('Impedance [Ohm]')
grid on

subplot(2,2,4)
plot(f, real(S11), 'b-', f, imag(S11), 'r-');
xlabel('Frequency [Hz]')r
ylabel('S11')
ylim([-1 1])
grid on

keyboard
return

Answer 1

[Walter Roberson]

https://www.mathworks.com/matlabcentral/fileexchange/48919-readtrc-read-r-s-trc-files-into-a-matlab-cell-array

or https://www.mathworks.com/matlabcentral/fileexchange/22908-read-spectrum-analyzer-trace-file with 'ag' option

or https://www.mathworks.com/matlabcentral/fileexchange/27614-biomed-reader-+-video-reader?focused=5169659&tab=function

[Weifu]

Hi, I'm using Matlab 2016b now and it seems this function does not correct due to textscan function error. Does textscan function changed for 2014 and 2016 Matlab? Thanks.

[Walter Roberson]

What error message are you seeing?

[Margareta Drozdikova]

Hi , I have some problem. I use readtrc function, I wrote readtrc('subor.trc') and error is

Subscript indices must either be

real positive integers or logicals.

Error in readtrc (line 20)
traces{k+1,1}=cell2mat(Columns(TracesIdx(size(TracesIdx))+4:size(Rows{1,1})));

Error in skuska1 (line 1)
readtrc('subor.trc')

how can I solve it?

thanks

[Walter Roberson]

Can you zip up the .trc file and attach the zip here?

[Marzena Rydygier]

Dear all,

have you been able to solve this problem? I have the same error:

Subscript indices must either be real positive integers or logicals.

Error in readtrc (line 20)
traces{k+1,1}=cell2mat(Columns(TracesIdx(size(TracesIdx))+4:size(Rows{1,1})));

Error in LeCroy_testy (line 5)
traces=readtrc('dane.trc');

I would be gratefull for your help!

[Walter Roberson]

Can you attach or link to the .trc file for testing?

[Alessandro Verniani]

The attached .trc file has both strings and integers, causing the readtrc function to error. If there are any solutions, please advise!

[Walter Roberson]

@Alessandro Verniani

That appears to be a binary .trc file, but the File Exchange contribution https://www.mathworks.com/matlabcentral/fileexchange/48919-readtrc-read-r-s-trc-files-into-a-matlab-cell-array is expecting only text files.

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