Problem with order of evaluation

*To*: mathgroup at smc.vnet.net*Subject*: [mg49940] Problem with order of evaluation*From*: Max Ulbrich <ulbrich at biochem.mpg.de>*Date*: Sat, 7 Aug 2004 03:51:33 -0400 (EDT)*Organization*: GWDG, Goettingen*Sender*: owner-wri-mathgroup at wolfram.com

Hi, I want to find a minimum in dependence of an initial condition of a differential eqaution. I can define a function f[y]: L=3.*^-9; g[y_]=NDSolve[{p''[x]==-1.*^9(43418E^(-38p[x])-43418E^(38p[x])),p[0]==-0.13,p'[0]==y},p[x],{x,0,L}] f[y_]:=((p[x]/.g[y]/.x->L)[[1]])^2 which evaluates properly: f[0.22*^8] However, Mathematica doesn't evaluate it properly when I try NMimimize, FindRoot or whatever: <<NumericalMath`NMinimize` NMinimize[f[y],{y,0.1*^8,0.3*^8}] How do I have to define f[y] that this works? Thanks a lot, Max