Re: Could someone else verify that an example from the

• To: mathgroup at smc.vnet.net
• Subject: [mg127318] Re: Could someone else verify that an example from the
• From: Geraghty Syd <sydgeraghty at mac.com>
• Date: Sun, 15 Jul 2012 23:43:37 -0400 (EDT)
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```On Jul 15, 2012, at 1:28 AM, W Craig Carter wrote:

> GraphicsGrid[Partition[Table[
>   NDSolve`Iterate[state, tau];
>   Plot3D[
>    Evaluate[
>     u[tau, x, y] /.
>      NDSolve`ProcessSolutions[state, "Forward"]], {x, -L, L}, {y, -L,
>      L}, PlotRange -> {-1/4, 1/4}],
>   {tau, 0, 20, 5}], 2]]

Hi Craig,

The issue that prevented your getting a solution was passing integer values for tau instead of Reals!

Table[NDSolve`Iterate[state, tau];
Plot3D[Evaluate[
u[tau, x, y] /.
NDSolve`ProcessSolutions[state, "Forward"]], {x, -L, L}, {y, -L,
L}, PlotRange -> {-1/4, 1/4}], {tau, 0, 20, 5}]
***********

Replace the range of tau by

{tau, 0., 20., 5.}

and you get the solution shown in the documentation with L=-10!

This is an example from Mathematica's lacking a great debugging environment or useful error messages which makes one want to tear out any remaining hair.

Hope that helps ...

Cheers .... Syd

Syd Geraghty B.Sc, M.Sc.

sydgeraghty at me.com

Mathematica 8.0 for Mac OS X x86 (64-bit) (February 23, 2011)
ReleaseID:    8.0.1.0 (2063982, 2063639)
MacOS X V 10.7.1 Lion
MacBook Pro 2.33 GHz Intel Core 2 Duo  3GB RAM

```

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