plot multiple PSD lines in single graph

Hi, i have two different PSD plot for two different file...but i am not able to plot these two in one graph ,because i want to compare both. here is a sample of my code...

signal = load('tremor_analysis.txt');

N = length(signal);

fs = 62.5; % 62.5 samples per second

fnyquist = fs/2; %Nyquist frequency

X_mags = abs(fft(signal));

bin_vals = [0 : N-1];

fax_Hz = bin_vals*fs/N;

N_2 = ceil(N/2);

semilogx(fax_Hz(1:N_2), 20*log10(X_mags(1:N_2)))

xlabel('Frequency (Hz)')

ylabel('Power (dB)');

title({'Single-sided Power spectrum' ... ' (Frequency in shown on a log scale)'});

axis tight

[Mohammad Monfared]

Have you tried 'hold on' after first call to 'semilogx'?

[md]

yup i tried but not working....

[Mohammad Monfared]

try the 'plot' instead of 'semilogx' and then 'hold on'. At the end add this:

 set(gca,'XScale','log')

[dpb]

For what definition of "not working"? That is NEVER a sufficient problem description.

There's no indication of a second plot in the posted code--either follow up the above with another data file and plot command after executing hold on or create the other dataset before plotting and plot both together by place them in the same call as columns in an array presuming you're using the same frequency binning for both.

[md]

@Mohammad Monfared, thank you brother its working.... =D

@dpb, thanks for your warm advice.... =D