[Visualpython-users] (no subject)

[<Art...@ao...>]

Bruce asked -

>>Sorry to be dense, but could you explain what this is and what it is for? 

One can create classes sub-classed from UserVector, adding whatever methods
and attributes one might need to extend the VPython vector, but use this 
"extended" vector as one might use the standard vector in VPython code.  And
the object created from the sub-class can interact with the native VPython 
vector, e.g one can "cross(v1,v2)" where v1 is inherited from UserVector and 
v2
is a native VPython vector.

>Perhaps a paragraph of intent/utility could be included in the module? 
>And/or a routine at the end illustrating its use?

Yeah being a little lazy there.  

I am using the UserVector in a dynamic geometry toy I have been iterating 
over for some time and now brining over to VPython.

It is mostly a self-education exercise - programming, graphics, synthetic 
geometry, analytic geometry, matrix algebra.  Considering my starting point
on all these subjects, I know how much I have gotten from the process and
have become quite an enthusiast of Python\Numeric as an educational tool
and see VPython as a perfect extension.

I do hope to have something to show interested folks in a few days - so I 
would
hope you might have a look at it and see from it how I utilized the 
UserVector.

ART