# my math functions

from math import pi
rad_deg_const = 180/pi

# sign function
def sign(n):
    if n < 0:
        return -1
    elif n > 0:
        return 1
    else:
        return 0

# convert from radians to degrees
def rad(deg):
    return deg/rad_deg_const

# convert from degrees to radians
def deg(rad):
    return rad*rad_deg_const