Re: Integration...

*To*: mathgroup at smc.vnet.net*Subject*: [mg24174] Re: Integration...*From*: Brian Higgins <bghiggins at ucdavis.edu>*Date*: Wed, 28 Jun 2000 22:50:55 -0400 (EDT)*References*: <8jc70h$df6@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Matt, If you know f(a)=f0 and g(a)=g0 and suppose f'(t)=F(t), and g'(t)=G(t). Then use NDSolve and plot the solution using ParametricPlot, i.e. sol=NDSolve[{f'[t]==F[t],g'[t]==G[t],f[a]==f0,g[a]==g0},{f,g},{t,a,b}] ParametricPlot[Evaluate[{f[t],g[t]}/.sol],{t,a,b}] You can readily extend this to plot the family of parametric curves for a specified range of f0, and g0. Cheers, Brian odIn article <8jc70h$df6 at smc.vnet.net>, "Yeung, Matthew" <m.yeung at ic.ac.uk> wrote: > Dear Sir, > > I am a Mathematica user and am having problems with one particular task that > I have to perform. > > I have 2 function, {f'(t),g'(t)}, that are unintegrable. I wish to plot the > parametric curve {f(t),g(t)} for a<t<b, say, but do not wish to use > NIntegrate as it will give me the result {f(T)-f(a),g(T)-g(a)}. > > Is there a way that I can find {f(a),g(a)} so that I can use NIntegrate; or > is it possible to evaluate the integral at one point? > > Thanks for your heklp and I look forward to hearing from you soon. > > Regards, > > Matt Yeung > > Sent via Deja.com http://www.deja.com/ Before you buy.