add demo for new spectral plot types

Author: toddrjen

examples/pylab_examples/spectrum_demo.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python
+# python
+
+from pylab import *
+
+dt = 0.01
+Fs = 1/dt
+t = arange(0, 10, dt)
+nse = randn(len(t))
+r = exp(-t/0.05)
+
+cnse = convolve(nse, r)*dt
+cnse = cnse[:len(t)]
+s = 0.1*sin(2*pi*t) + cnse
+
+subplot(3, 2, 1)
+plot(t, s)
+
+subplot(3, 2, 3)
+magnitude_spectrum(s, Fs=Fs)
+
+subplot(3, 2, 4)
+magnitude_spectrum(s, Fs=Fs, scale='dB')
+
+subplot(3, 2, 5)
+angle_spectrum(s, Fs=Fs)
+
+subplot(3, 2, 6)
+phase_spectrum(s, Fs=Fs)
+
+show()