Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2008

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Another Out of Memory Problem

  • To: mathgroup at smc.vnet.net
  • Subject: [mg91331] Re: Another Out of Memory Problem
  • From: Roland Franzius <roland.franzius at uos.de>
  • Date: Sat, 16 Aug 2008 05:53:17 -0400 (EDT)
  • References: <g8137j$19$1@smc.vnet.net>

Kevin J. McCann schrieb:
> I can do the following:
> 
> Integrate[Cos[2*x]*
>       Exp[I*z*Cos[x]],
>     {x, -Pi, Pi}]
> 
> 
> which produces a Bessel function answer; however if I change the
> argument in the cosine to 2.5 as in:
> 
> Integrate[Cos[2.5*x]*
>       Exp[I*z*Cos[x]],
>     {x, -Pi, Pi}]
> 
> I almost immediately get this:
> 
> No more memory available.
> Mathematica kernel has shut down.
> Try quitting other applications and then retry.
> 
> Any ideas why? I am running XP with 2Gb of memory.


Start the task manager (Alt+Ctrl+Del) and keep track of the memory in use.

Windows class A Mathematica is able to adress 2 GB of memory maximally.

Since it is running atop the Windows Desktop it is not able to issue the 
"out of memory" warning because of lack of memory in its own adress 
space, the old windows blue screen trap.

With a machine that is able to adress 3 GB the warning is issued.

With a 2 GB machine it is a question of how much memory is allocated for 
the graphics system. With less than 2 GB available the kernel crases on 
memory overflow.


Integrate[Cos[2.5`20*x]*Exp[I*z*Cos[x]],
  {x, -Pi, Pi}]

consumes about 1GB maximum of memory while

Integrate[Cos[2.5*x]*Exp[I*z*Cos[x]],
  {x, -Pi, Pi}]

needs around 1.97 GB and begins to block the task manager as well as the 
windows event handler.  Its difficult to reach the Abort menu activation

2 GB intel dual core Windows Vista system.


-- 

Roland Franzius


  • Prev by Date: Re: fractional derivative of 1/(log x)?
  • Next by Date: Re: No Memory Available
  • Previous by thread: Re: Another Out of Memory Problem
  • Next by thread: NDSolve precision and velocity problem