Re: Performance improvement needed - Help.
- To: mathgroup at smc.vnet.net
- Subject: [mg63594] Re: Performance improvement needed - Help.
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Fri, 6 Jan 2006 05:24:43 -0500 (EST)
- Organization: The University of Western Australia
- References: <dpiotv$l11$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
In article <dpiotv$l11$1 at smc.vnet.net>, "Tonybony" <aneves at gmail.com>
wrote:
> I am trying to improve the performance of a bottle neck operation. I've
> used functional programming and read about Packed Arrays. My current
> operation is:
>
> Efunc[k_, x_, y_, z_] := Radialf[k, VNmax, x, y,z].Map[(MMatrix[[# -
> Nmin + 1]].SphericalHarmonicY[#, Range[-#, #],Theta[x, y, z], Phi[x,
> y]]) &, VNmax, {1}];
>
> EMatrix= Apply[Efunc[k, #1, #2, 0.0] &, Grid, {2}];
It looks like you are computing some atomic or molecular integral via
quadrature (or maybe just a simple sum) on a discrete cartesian grid?
> Where I defined,
> GridX = Range[Xini, Xfin, Xinc];
> Grid = Outer[List, GridX, GridX];
> VNmax = Range[Nmin, Nmax];
> GridG = Table[{n, m}, {n, Nmin, Nmax}, {m, -n, n}];
> Radial[k_, n_, x_, y_, z_] := BesselJ[n,k Sqrt[x^2+y^2+z^2]];
> MMatrix= Apply[(Exp[-#2 fio] MAmpl[[#1 - Nmin + 1, Abs[#2] + 1]]
> MI1[[#1 - Nmin + 1, Abs[#2] + 1]] Cosfio) &, GridG, {2}];
>
> I have tried the command,
> GridG = Developer`ToPackedArray[Table[{n, m}, {n, Nmin, Nmax}, {m, -n,
> n}]];
> To see if I could build a packed array so that I could better
> performance, but didn't succeed. Maybe I am creating a wrong array, but
> I don't know of any alternative.
>
> For each element of GridG I have a pair of point (x,y) that I pass
> along a set of function for calculations. Is their an efficient way of
> doing this?
Do you have a reference for the integrals that you are trying to
compute. There are many ways to speed up the computation of integrals
over hydrogenic orbitals.
Cheers,
Paul
_______________________________________________________________________
Paul Abbott Phone: 61 8 6488 2734
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