Services & ResourcesWolfram ForumsMathGroup Archive

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

Re: Re: NDSolve Mathematica 6 and 7

• To: mathgroup at smc.vnet.net
• Subject: [mg103368] Re: [mg103364] Re: [mg103336] NDSolve Mathematica 6 and 7
• From: David Szekely <D.Szekely at victorchang.edu.au>
• Date: Fri, 18 Sep 2009 05:37:40 -0400 (EDT)
• References: <200909160946.FAA12985@smc.vnet.net>,<200909171021.GAA29345@smc.vnet.net>

I have the same problems as Mark. It seems that every NDSolve evaluation I 
do is significantly faster in V6 than V7. Anyone have any ideas why?

Dave
________________________________________
From: DrMajorBob [btreat1 at austin.rr.com]
Sent: Thursday, September 17, 2009 8:21 PM
To: mathgroup at smc.vnet.net
Subject: [mg103368] [mg103364] Re: [mg103336] NDSolve Mathematica 6 and 7

Send details, Mark. Details.

Bobby

On Wed, 16 Sep 2009 04:46:29 -0500, Mark Perrin <m.perrin at me.com> wrote:

> I was wondering if anyone could help me. I am solving a set of partial
> and ordinary differential equations in Mathematica 7. For the same set
> of equations and same expression i.e.
>
> solution =
>   NDSolve[EQNS, STATES, {t, 0, 500}, {x, 0, 1.6}, MaxStepSize -> {1,
> 0.01},
>    MaxSteps -> Infinity, AccuracyGoal -> 5, PrecisionGoal -> 5]
>
> where EQNS are the ODEs.
>
> Mathematica 6 solves this in < 5 minutes.
> Mathematica 7 takes about 40-45 minutes.
> for the same solution.
>
> Same hardware etc.
>
> Can anyone please tell me if it is possible to speed up the solution
> in Mathematica 7. Why would the two be so different?
>
> Kind Regards,
>
> Patch
>


--
DrMajorBob at yahoo.com


Scanned by Messagelabs ***

• References:
  • NDSolve Mathematica 6 and 7
    • From: Mark Perrin <m.perrin@me.com>
  • Re: NDSolve Mathematica 6 and 7
    • From: DrMajorBob <btreat1@austin.rr.com>