Re: serious NDSolve bug?
- To: mathgroup at smc.vnet.net
- Subject: [mg44026] Re: serious NDSolve bug?
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Sat, 18 Oct 2003 03:12:17 -0400 (EDT)
- Organization: Universitaet Leipzig
- References: <bmod0f$hof$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
- Sender: owner-wri-mathgroup at wolfram.com
Hi, and whe you write f[kampas_?NumericQ]:=(u[\[Xi]] /. First[sprendinys1 = NDSolve[{Derivative[2][\[Psi]][\[Xi]] == (\[Xi]^2 - energija)* \[Psi][\[Xi]], Derivative[1][u][\[Xi]] == \[Psi][\[Xi]]^2, \[Psi][\[Xi]min] == 0, Derivative[1][\[Psi]][\[Xi]min] == kampas, u[\[Xi]min] == 0}, {\[Psi][\[Xi]], u[\[Xi]]}, {\[Xi], \[Xi]min, \[Xi]max}]] /. \[Xi] -> \[Xi]max) and call teisingasKampas = FindRoot[f[kampas]==1, {kampas, -0.04, 0.04}] all works as expected *and* your code is better readable. BTW: Can you avoid postings with Mathematica's special characters ? Regards Jens Artþras Acus wrote: > > Hi, All > > In version 4.1 the following code works as expected. > > \[Xi]min = -5; energija = 2*n + 1 /. n -> 1; \[Xi]max = 5; > > teisingasKampas = > FindRoot[ > (u[\[Xi]] /. First[sprendinys1 = > NDSolve[{Derivative[2][\[Psi]][\[Xi]] == (\[Xi]^2 - energija)* > \[Psi][\[Xi]], Derivative[1][u][\[Xi]] == \[Psi][\[Xi]]^2, > \[Psi][\[Xi]min] == 0, > Derivative[1][\[Psi]][\[Xi]min] == kampas, u[\[Xi]min] == 0}, > {\[Psi][\[Xi]], u[\[Xi]]}, > {\[Xi], \[Xi]min, \[Xi]max}]] /. \[Xi] -> \[Xi]max) == 1, > {kampas, -0.04, 0.04}] > > In 5.0 I get message, that kampas is not a number. Changing FindRoot[ ] > by RootSearch[] (from Ted Ersek package) did not help, therefore I > suspect that there is serious bug in NDSolve argument evaluation > procedure. How I can make it to work ? > > Sincerely, Arturas Acus