Integrate memory usage in 1.2 vs. 2.x
- To: mathgroup at yoda.physics.unc.edu
- Subject: Integrate memory usage in 1.2 vs. 2.x
- From: Erik Sowa <sowa at amdew.llnl.gov>
- Date: Tue, 12 Oct 93 15:22:39 -0700
I have a piece of mma code that runs just fine under version 1.2 but
runs out of memory on version 2.x. Specifically, it works under 1.2 on a
Decstation. It dies with "Out of memory. Exiting." under 2.x whether it
is run from a front end or from a shell. I have tried it under 2.0 on a
Decstation and under 2.2 on an IBM RS600 with 256M (!!!) of memory. Can
anyone suggest why this might be? Is there some memory management
mumbo-jumbo to perform under 2.x, or have the integration routines
become more memory intensive, or is it something else? Any help would be
appreciated. The code in question:
Needs["Utilities`ShowTime`"];
Ylm[l_Integer,m_Integer] :=
SphericalHarmonicY[l,m,theta,phi] //.
{E^(Complex[0,n_]*phi) -> ((x+I y)/Sqrt[x^2+y^2])^n,
Cos[theta] -> z/Sqrt[x^2+y^2+z^2],
Sin[theta] -> Sqrt[x^2+y^2]/Sqrt[x^2+y^2+z^2]}
QlmKernel[l_Integer,m_Integer] :=
(x^2+y^2+z^2)^(l/2) * Ylm[l,m]
Qlm[l_Integer,m_Integer] :=
Integrate[QlmKernel[l,m],
{x,-1/2,1/2},{y,-1/2,1/2},{z,-1/2,1/2}]
Table[{ll,mm,Qlm[ll,mm]},
{ll,62,62,2},{mm,0,ll,4}]
(Obviously I want to run the loop over more than just ll=62 but that
case is sufficient to demonstrate the problem.)
--
erik sowa (sowa at amdew.llnl.gov)