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Topic: NDSolve differences between mathematica 8 and 9
Replies: 1   Last Post: Jan 26, 2013 1:38 AM

 Alex Krasnov Posts: 15 Registered: 10/3/12
Re: NDSolve differences between mathematica 8 and 9
Posted: Jan 26, 2013 1:38 AM

I do not have Mathematica 9 here. However, one issue with your expression
is that the symbol for the imaginary unit begins with a capital letter, as
do all other built-in Mathematica symbols.

Alex

On Fri, 25 Jan 2013, Teresa wrote:

> Hello,
>
> I am using mathematica 9 and having some problems with a particular expression, but when I tried it on mathematica 8 it worked perfectly. My expression is:
>
> NDSolve[{D[T[n,z],n]+i 2 D[T[n,z],{z,2}]+z^2 T[n,z]==0,T[0,z]==1,Derivative[0,1][T][n,5]==0,Derivative[0,1][T][n,0]==0},T,{n,0,5},{z,0,5}]
>
> where i is the imaginary number, and on both I had a new window to work on, with nothing having been done previously on it.
>
> Mathematica 8 gave me this:
> {{T-> InterpolatingFunction[{{0.,5.},{0.,5.}},<>]}}
>
> and mathematica 9 gave me this:
> NDSolve::ndnum : Encountered non-numerical value for a derivative at n==0.`.>>
>
> Does anyone know what is going on here? I cannot use mathematica 8, as I do not have continual access to that machine.
>
> Thank you for your help.
>