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serious NDSolve bug?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg44000] serious NDSolve bug?
  • From: Artūras Acus <acus at itpa.lt>
  • Date: Fri, 17 Oct 2003 05:14:25 -0400 (EDT)
  • Organization: Institute of Theoretical Physics and Astronomy
  • Sender: owner-wri-mathgroup at wolfram.com

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


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