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"""
Implements mainly the Vector class. See its documentation.
"""
class VectorError(Exception):
"""
An exception to use with Vector
"""
def __init__(self, msg):
self.msg = msg
def __str__(self):
return repr(self.value)
class Vector(tuple):
"""
A vector.
"""
def __init__(self,seq):
tuple.__init__(seq)
def __add__(self, other):
if not(isinstance(other,Vector)):
raise VectorError("right hand side is not a Vector")
return Vector(map(lambda x,y: x+y, self, other))
def __neg__(self):
return Vector(map(lambda x: -x, self))
def __pos__(self):
return self
def __sub__(self, other):
return Vector(map(lambda x,y: x-y, self, other))
def __mul__(self, other):
if not(isinstance(other,int) or isinstance(other,float)):
raise VectorError("right hand side is illegal")
return Vector(map(lambda x: x*other, self))
def __rmul__(self, other):
return (self*other)
def __div__(self, other):
if not(isinstance(other,int) or isinstance(other,float)):
raise VectorError("right hand side is illegal")
return Vector(map(lambda x: x/other, self))
def __rdiv__(self, other):
raise VectorError("you sick pervert! you tried to divide something by a vector!")
def __and__(self,other):
"""
this is a dot product, done like this: a&b
must use () around it because of fucked up operator precedence.
"""
if not(isinstance(other,Vector)):
raise VectorError("trying to do dot product of Vector with non-Vector")
"""
if self.dim()!=other.dim():
raise("trying to do dot product of Vectors of unequal dimension!")
"""
d=self.dim()
s=0.
for i in range(d):
s+=self[i]*other[i]
return s
def __rand__(self,other):
return self&other
def __or__(self,other):
"""
cross product, defined only for 3D Vectors. goes like this: a|b
don't try this on non-3d Vectors. must use () around it because of fucked up operator precedence.
"""
a=self
b=other
return Vector([a[1]*b[2]-a[2]*b[1],a[2]*b[0]-a[0]*b[2],a[0]*b[1]-a[1]*b[0]])
def __ror__(self,other):
return -(self|other)
def __abs__(self):
s=0.
for x in self:
s+=x**2
return s**(1.0/2)
def __iadd__(self,other):
self=self+other
return self
def __isub__(self,other):
self=self-other
return self
def __imul__(self,other):
self=self*other
return self
def __idiv__(self,other):
self=self/other
return self
def __iand__(self,other):
raise VectorError("please don't do &= with my Vectors, it confuses me")
def __ior__(self,other):
self=self|other
return self
def __repr__(self):
return "Vector("+tuple.__repr__(self)+")"
def norm(self):
"""
gives the Vector, normalized
"""
return self/abs(self)
def dim(self):
return len(self)
def copy(self):
return Vector(self)
################################################################################################
def zeros(n):
"""
Returns a zero Vector of length n.
"""
return Vector(map(lambda x: 0., range(n)))
def ones(n):
"""
Returns a Vector of length n with all ones.
"""
return Vector(map(lambda x: 1., range(n)))
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