Power spectral density plot correction

Hello, I want to make a power spectral density estimate using periodogram and welch method and I need to plot them in one graph,

I have this simple script (my data are different I just want this code to be simple):

    n = 0:319;
    x = cos(pi/4*n) + randn(size(n));
    
    pwelch(x)
    hold on
    periodogram(x,rectwin(length(x)),length(x))

The result is what it should be, but the graphs are in the same color, so it is unrecognizable what was done using pwelch and what using periodogram, how can I set different colours of the lines?

Thank you very much

Answer 1

[Sriram Tadavarty]

Hi Petr,

By default, you cannot change the color of output from the functions. However, you can do slight modification to the code to make the clear distinction. Here is the code, update the periodogram function with outputs and plot it. However, this can be applied even for pwelch.

[pxx,w] = periodogram(x,rectwin(length(x)),length(x));
plot(w,10*log10(pxx),'r')

Hope this helps.

Regards,

Sriram