[Numpy-discussion] Can this function by Numpy-ized?

[Rob]

The good news is that your routine reduces execution time by 30%.  The
bad news is that the wrong numbers are coming out of it.  I'm trying
some otner permutations of "take" and "add.reduce" in the function to
see if I can get it.  One method that worked was splitting up "c" into
c1,c2,c3, such that:

c1=Numeric.take(a.NodeCord[:,0],TrngleNode)
etc

and then using  Numeric.add.reduce(s*c1,1)
etc

This gives the right results, but is slower than plain Python.  I'll
keep at it.  Thanks again.


"Paul F. Dubois" wrote:
> 
> def cgqp(QuadPoint, TrngleNode, a):
>     s = a.Qpnt[Quadpoint,:]
>     c = Numeric.take(a.NodeCord, TrngleNode)
>     return Numeric.add.reduce(s * c, axis=1)
> 
> This may or may not be right. The data structures I would have to set up
> to test it are too much for Sunday morning.
> 
> -----Original Message-----
> From: numpy-discussion-admin at lists.sourceforge.net
> [mailto:numpy-discussion-admin at lists.sourceforge.net] On Behalf Of Rob
> Sent: Sunday, August 26, 2001 8:39 AM
> To: numpy-discussion at lists.sourceforge.net.
> Subject: [Numpy-discussion] Can this function by Numpy-ized?
> 
> I finally got my FEM EM code working.  I profiled it and this function
> uses up a big hunk of time.  It performs gaussian integration over a
> triangle.  I am trying to figure out how to slice the arrays so as to
> push it down into the C level.  Does anyone have any ideas?  Thanks,
> Rob.
> 
> ps. it looks to be intractible to me.  Maybe I need to look at writing a
> C extension.  I've never done that before.
> 
> ##**********************************************************************
> *****
> ##Prototype:  void  ComputeGaussQuadPoint(int QuadPoint, int
> *a.TrngleNode,
> ##                                            double *SrcPointCol)
> ##Description: To compute the coordinates of 7-point Gauss nodes of
> ##             a triangular patch.
> ##Input value:
> ##    int QuadPoint  --- node index, it can be from 0 to 6.
> ##    int *a.TrngleNode  ---  the three nodes of a tringular patch.
> ##    double *SrcPointCol --- where to store the results
> ##Return value: none
> ##Global value used: a.NodeCord, a.Qpnt
> ##Global value modified:    none
> ##Subroutines called:    none
> ##Note: Not very sure.
> ************************************************************************
> ****
> def ComputeGaussQuadPoint(QuadPoint,TrngleNode,a):
> 
>     SrcPointCol=zeros((3),Float)
> 
>     SrcPointCol[0] =   a.Qpnt[QuadPoint,0]*a.NodeCord[TrngleNode[0],0]\
>                      + a.Qpnt[QuadPoint,1]*a.NodeCord[TrngleNode[1],0]\
>                      + a.Qpnt[QuadPoint,2]*a.NodeCord[TrngleNode[2],0]
> 
>     SrcPointCol[1] =   a.Qpnt[QuadPoint,0]*a.NodeCord[TrngleNode[0],1]\
>                      + a.Qpnt[QuadPoint,1]*a.NodeCord[TrngleNode[1],1]\
>                      + a.Qpnt[QuadPoint,2]*a.NodeCord[TrngleNode[2],1]
> 
>     SrcPointCol[2] =   a.Qpnt[QuadPoint,0]*a.NodeCord[TrngleNode[0],2]\
>                      + a.Qpnt[QuadPoint,1]*a.NodeCord[TrngleNode[1],2]\
>                      + a.Qpnt[QuadPoint,2]*a.NodeCord[TrngleNode[2],2]
> 
> 
>     return SrcPointCol
> 
> 
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> 
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> 
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