Re: ndsolve ndsv problem
- To: mathgroup at smc.vnet.net
- Subject: [mg80847] Re: ndsolve ndsv problem
- From: Chris Chiasson <chris.chiasson at gmail.com>
- Date: Tue, 4 Sep 2007 03:42:45 -0400 (EDT)
- References: <email@example.com>
On Aug 6, 2:37 am, "Chris Chiasson" <ch... at chiasson.name> wrote: > Steps to reproduce: > 1. Issue this command (given to you in InputFrom due to a copy/paste problem) > > NDSolve[0.0005635632304299039*psi[R] == > (2*Derivative[psi][R])/R + > Derivative[psi][R] && > Derivative[psi] == 7.017487714753473 && > psi[Infinity] == 0, psi, R] > > 2. Notice the warning (input returns unevaluated): > > NDSolve::ndsv: Cannot find starting value for the variable psi^\[Prime]. >> > > 3. The documentation for this error says: > > Generated when NDSolve is unable to solve the initial conditions to > find a starting value in an initial value problem. > This message can be generated by a variety of errors in the > specification of initial conditions. > > Expected result: > Something more helpful > > Maybe I am being too hard on Mathematica here, but maybe not, > considering what Rob Knapp said in 1999 about Mathematica 4:http://forums.wolfram.com/mathgroup/archive/2000/Jun/msg00070.html > > Also, it appears the documentation hasn't changed for this error:http://forums.wolfram.com/mathgroup/archive/2000/Jun/msg00068.html > > --http://chris.chiasson.name/ 1999 -> 2000 ...