# Vectors 0.0.1
# Copyright 2001-2004 Lja MultiMedia
# May be used under the GNU GPL

"""vectors : basic vector class and related functions"""

from __future__ import division
import math

class vector(tuple):
	def normalize(self):
		t = 0
		for n in self:
			t += n
		l = len(self) 
		r = [None] * l
		for i in range(l):
			r[i] = self[i] / t
		return self.__class__(r)
	def __add_num(self, num):
		l = len(self) 
		r = [None] * l
		for i in range(l):
			r[i] = self[i] + num
		return self.__class__(r)
	def __add_seq(self, seq):
		l = len(self)
		assert(l == len(seq))
		r = [None] * l
		for i in range(l):
			r[i] = self[i] + seq[i]
		return self.__class__(r)
	def __add__(self, other):
		if isinstance(other, (int, long, float)):
			return self.__add_num(other)
		elif isinstance(other, (tuple, list)):
			return self.__add_seq(other)
		else:
			raise 'FIXME'
	def __mul_num(self, num):
		l = len(self)
		r = [None] * l
		for i in range(l):
			r[i] = self[i] * num
		return self.__class__(r)
	def __mul_seq(self, seq):
		l = len(self)
		assert(l == len(seq))
		r = [None] * l
		for i in range(l):
			r[i] = self[i] * seq[i]
		return self.__class__(r)
	def __mul__(self, other):
		if isinstance(other, (int, long, float)):
			return self.__mul_num(other)
		elif isinstance(other, (tuple, list)):
			return self.__mul_seq(other)
		else:
			raise 'FIXME'
	def __neg__(self):
		l = len(self)
		r = [None] * l
		for i in range(l):
			r[i] = -self[i]
		return self.__class__(r)
	def __str__(self):
		return tuple.__repr__(self)
	def __repr__(self):
		return "%s(%s)" % (self.__class__.__name__, tuple.__repr__(self))

def distance(a, b, sq=0):
	"""distance(sequence, sequence) --> float"""
	l = len(a)
	assert(len(b) == l)
	d = 0
	for i in range(l):
		d += (a[i] - b[i]) ** 2
	if sq:
		return d
	return math.sqrt(d)

def direction(a, b):
	"""direction(sequence, sequence) --> vector"""
	l = len(a)
	assert(len(b) == l)
	d = list()
	for i in range(l):
		d.append(a[i] - b[i])
	return vector(d).normalize()

def _test():
	a = vector((13, 8))
	a2 = eval(repr(a))
	assert(a == a2)
	for b in (a2, (2, -1), 42):
		print a, '+', b, '=', a + b
	print vector((3, 3, 3)).normalize()
	assert(len(a * 0.0) == 2)
	print 'All tests passed!'

if __name__ == "__main__":
	_test()