from spectrum import arma2psd, ma, marple_data
import pylab

# Estimate 15 Ma parameters
b, rho = ma(marple_data, 15, 30)
# Create the PSD from those MA parameters
psd = arma2psd(B=b, rho=rho, sides='centerdc')
# and finally plot the PSD
pylab.plot(pylab.linspace(-0.5, 0.5, 4096), 10 * pylab.log10(psd/max(psd)))
pylab.axis([-0.5, 0.5, -30, 0])