ScientificPython имеет класс Vector . например:
In [1]: from Scientific.Geometry import Vector
In [2]: v1 = Vector(1, 2, 3)
In [3]: v2 = Vector(0, 8, 2)
In [4]: v1.cross(v2)
Out[4]: Vector(-20.000000,-2.000000,8.000000)
In [5]: v1.normal()
Out[5]: Vector(0.267261,0.534522,0.801784)
In [6]: v2.cross(v1)
Out[6]: Vector(20.000000,2.000000,-8.000000)
In [7]: v1*v2 # dot product
Out[7]: 22.0