Re: NDSolve differences between mathematica 8 and 9

*To*: mathgroup at smc.vnet.net*Subject*: [mg129584] Re: NDSolve differences between mathematica 8 and 9*From*: Alex Krasnov <akrasnov at eecs.berkeley.edu>*Date*: Sat, 26 Jan 2013 01:40:36 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <20130125063352.E5EBC68A8@smc.vnet.net>

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. >

**References**:**NDSolve differences between mathematica 8 and 9***From:*Teresa <teresajane88@gmail.com>