plot a discrete signal

[x,fs2,nbits2]= wavread('w.wav');
stem(x);

I want to plot a 20 samples section of x.

Answer 1

[Adam]

stem(x(1:20))

will plot the first 20 samples of x, assuming it has that many. Or

stem(x(345:364))

etc, to plot some other arbitrary section of 20 samples.