gazesim/code/vector.py

from math import sqrt
from numpy import array

'''
Vector object has the same functionality as VPython's vector. 
this module is used when only vector processing is required and
VPython is not available (e.g. non-Windows platforms)
'''

class Vector:
	x, y, z = (0.0, 0.0, 0.0)

	def __init__(self, *xyz):
		if len(xyz) == 1:
			xyz = xyz[0]
		if isinstance(xyz, Vector):
			self.x, self.y, self.z = xyz.x, xyz.y, xyz.z
		else:
			if len(xyz) == 2: xyz = xyz[0], xyz[1], 0
			self.x, self.y, self.z = xyz
		self.__update__()

	def __update__(self):
		self.mag = sqrt(self.x**2 + self.y**2 + self.z**2) 

	def norm(self):
		return Vector(self.x/self.mag, self.y/self.mag, self.z/self.mag)

	def dot(self, other):
		return self.x*other.x + self.y*other.y + self.z*other.z

	def cross(self, other):
		return Vector(self.y*other.z - self.z*other.y,
					  self.z*other.x - self.x*other.z,
					  self.x*other.y - self.y*other.x)

	def tuple(self):
		return self.x, self.y, self.z
	def __array__(self):
		return array(self.tuple())

	def __radd__(self, other):
		return self.__add__(other)
	def __add__(self, other):
		return Vector(self.x + other.x, self.y + other.y, self.z + other.z)
	def __rsub__(self, other):
		return self.__sub__(other)
	def __sub__(self, other):
		return Vector(self.x - other.x, self.y - other.y, self.z - other.z)

	def __rtruediv__(self, scalar):
		return self.__div__(scalar)
	def __rfloordiv__(self, scalar):
		return self.__div__(scalar)
	def __truediv__(self, scalar):
		return self.__div__(scalar)
	def __floordiv__(self, scalar):
		return self.__div__(scalar)
	def __div__(self, scalar):
		scalar = float(scalar)
		return Vector(self.x/scalar, self.y/scalar, self.z/scalar)

	def __mul__(self, scalar):
		return self.__rmul__(scalar)
	def __rmul__(self, scalar):
		return Vector(self.x*scalar, self.y*scalar, self.z*scalar)

	def __neg__(self):
		return self*-1

	def __repr__(self):
		return '({0}, {1}, {2})'.format(self.x, self.y, self.z)