# this is the template for Lab #3, Task #4
import matplotlib.pyplot as p
import math,numpy,random
import lab3

def receive(samples,samples_per_bit=4,vth=0.5):
    """
    Apply a statistical measure to samples to determine which
    sample in the bit cell should be used to determine the
    transmitted message bit.  vth is the digitization threshold.
    Return a sequence or array of received message bits.
    """
    pass # your code here

def bit_error_rate(seq1,seq2):
    """
    Perform a bit-by-bit comparison of two message sequences,
    returning the fraction of mismatches.
    """
    pass # your code here

if __name__ == '__main__':
    message = [random.randint(0,1) for i in xrange(1000000)]
    noisy_data = lab3.transmit(message,samples_per_bit=4,nmag=1.0)
    received_message = receive(noisy_data)
    ber = bit_error_rate(message,received_message)
    print "bit error rate = %g" % ber