from pylab import *


def quantize(val, possible_values):
    best_match = None
    best_match_difference = 0
    for bit_value in possible_values:
        difference = abs(bit_value-val)
        if best_match is None or difference < best_match_difference:
            best_match = bit_value
            best_match_difference = difference
    print(best_match)
    return best_match


t = arange(0,1, 0.01)
y = sin(2*pi*t)
possible = [-2,-1,0,1]

y1 = []
for t1 in y:
    y1.append(quantize(t1, possible))

subplot(2,1,1)
plot(y)
subplot(2,1,2)
plot(y1)

show()