sin.py - program to find the sine of an angle by iteration http://en.wikipedia.org/wiki/Sine#Series_definition

sin.py

#!/usr/bin/python
"""
    sin.py - program to find the sine of an angle by iteration
    http://en.wikipedia.org/wiki/Sine#Series_definition

"""
# Isn't it obivious ?
from math import factorial, pi


deg_x = int(input('Enter angle in degrees:'))
# Convert to radian
x = (pi/180)*deg_x
sinx = 0.0
#Number of iterations
iterations = 20

# See http://en.wikipedia.org/wiki/Sine#Series_definition
for n in range(0, iterations):
    # Calculating in 2 steps for clarity
    increment = (x ** (2*n+1)) / factorial(2*n+1)
    increment = increment * ((-1)**n)
    sinx = sinx + increment

print "sin(", deg_x ,") = ", sinx