Assignment2 DSP

assignment2.py

from scipy import signal
import numpy as np

def pitohz(x):
	return x/(np.pi*2)

def prototype_filter():
    """ ASSIGNMENT 2

        Compute the prototype filter used in subband coding. The filter
        is a 512-point lowpass FIR h[n] with bandwidth pi/64 and stopband
        starting at pi/32

        You should use the remez routine (signal.remez()). See
        http://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.remez.html
    """
    
    # In put is in hz, thus need to be converted to the right scale
    # Output is a passband at 0,pi/64 with gain 2
    # And a stop band at pi/32 -> pi

    # Your code goes here
    return signal.remez(512, [0.0, pitohz(np.pi/64.), pitohz(np.pi/32.), pitohz(np.pi)], [2.0, 0.0])