InterpolatingFunction

*To*: mathgroup at smc.vnet.net*Subject*: [mg4947] InterpolatingFunction*From*: Noriaki Kinoshita <nk204 at cam.ac.uk>*Date*: Mon, 7 Oct 1996 02:02:14 -0400*Sender*: owner-wri-mathgroup at wolfram.com

I have a question about using a InterpolatingFunction obtained by NDSolve as a usual function. I posted similar questions ealier last month, and received much help to which I am very grateful. First I ran: NDSolve{c'[k]==...,w'[k]==...,c[ks]==cs,w[ks]==ws},{c,w},{k,ks,k0}] Then I got: {{c->InterpolatingFunction [...], w->InterpolatingFunction [...]}} Next I ran, using the above result: NDSolve[{k'[t]==0.715c[k[t]]+... /. %..%[[1]],k[0]==0.3},k,{t,0,40}] Then I successfully (with the helpful suggestions from MathGroup) got {{k->InterpolatingFunction [...]}} Now there is a problem that I can not solve. I want to look at how c[k[t]] moves as t moves from 0 to 40. I found in page212 of the last edition of 'Mathematica' book the following command and tried it. k /. First[%] which allowed me to plot k[t] by: Plot[%[t],{t,0,40}] When I similarly tried to plot c[k[t]] by: Plot[%%%%[%[t],{t,0,40}] ^this is supposed to mean c[k] obtained by c/. First[%] immediately after getting {c->InterpolatingFunction[ ]} Then I got a very strange looking plot together with some error messages. Can anybody suggest what went wrong? Noriaki Kinoshita University of Cambridge ==== [MESSAGE SEPARATOR] ====