Determining point position

point_position.py

# https://pp.vk.me/c625329/v625329501/1e47/wWQSR_4v0bA.jpg

import math

def spo(color, x, y):
	result = {
	  'red': lambda x,y: x + 10/(x+y),
	  'blue': lambda x,y: x + 1/y,
	  'yellow': lambda x,y: x/(y-x),
	  'white' : lambda x,y: x * y
	}[color](x, y)
	print('Color: ' + color)
	print('SPO = ' + str(result))
	
def sign(n):
	if n == 0:
		return 0;
	return abs(n)/n
	
def isInsideTriangle(xa, ya, xb, yb, xc, yc, xp, yp):
	a = (xa-xp)*(yb-yp)-(xb-xp)*(ya-yp)
	b = (xb-xp)*(yc-yp)-(xc - xp)*(yb-yp)
	c = (xc-xp)*(ya-yp)-(xa - xp)*(yc-yp)
	return sign(a)==sign(b) and sign(b)==sign(c)

print("Enter radius")
r = float(input("R = "))
# circle center
x0 = r 
y0 = -r
print("Enter point coordinates")
x = float(input("x = "))
y = float(input("y = "))

if (x > 0 and y > 0) or (x < 0 and y > 0) or (x < 0 and y < 0):
	spo('yellow', x, y)
else:
	r_xy = math.sqrt((x0-x)*(x0-x)+(y0-y)*(y0-y))
	if r_xy <= r:
		print("Point belongs to the circle")
		if x >= r:
			if y < -r:
				#print("sector 2") # bottom right
				if isInsideTriangle(r, -r, 2*r, -r, r, -2*r, x, y):
					spo('white', x, y)
				else:
					spo('blue', x, y)
			else:
				#print("sector 1") # top right
				if isInsideTriangle(r, -r, r, 0, 2*r, -r, x, y):
					spo('white', x, y)
				else:
					spo('red', x, y)
		else:
			if y < -r:
				#print("sector 3") # bottom left
				if isInsideTriangle(0, -r, r, -r, r, -2*r, x, y):
					spo('white', x, y)
				else:
					spo('red', x, y)
			else:
				#print("sector 0") # top left
				if isInsideTriangle(0, -r, r, 0, r, -r, x, y):
					spo('white', x, y)
				else:
					spo('blue', x, y)
	else:
		print("Point does not belongs to the circle")
		if x > r and y < -r:
			spo('yellow', x, y)
		else:
			spo('white', x, y)