# import matplotlib
# matplotlib.use('agg')
import matplotlib.pyplot as plt
import math

# plot the modified cosine function as a unit of degrees
#  intent is to find 'goodness' function giving max result at 
#  multiples of 90 degrees

degrees = []
cosines = []

for i in range(0, 360):
  degrees.append(i)
  cosines.append(math.fabs(math.cos(2 * math.radians(i))))

plt.plot(degrees, cosines)
plt.ylabel("fabs(cos(2 * radians(i)))")
plt.xlabel("degrees")
plt.show()