Re: Using NDSolve and Finding a specific Value

*To*: mathgroup at smc.vnet.net*Subject*: [mg85369] Re: [mg85354] Using NDSolve and Finding a specific Value*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Thu, 7 Feb 2008 06:39:17 -0500 (EST)*Reply-to*: hanlonr at cox.net

Clear[sols]; sols = i /. NDSolve[{i'[t] == (1/8.516011) (-i[t] + 0.596120754), i[1] == 0.219319}, i, {t, 1, 4}][[1]]; sols[3.8] 0.324902 Plot[sols[t], {t, 1, 4}] Clear[sols]; sols = NDSolve[{i'[t] == (1/8.516011) (-i[t] + 0.596120754), i[1] == 0.219319}, i, {t, 1, 4}][[1]]; i[3.8] /. sols 0.324902 Plot[i[t] /. sols, {t, 1, 4}] Bob Hanlon ---- Tara.Ann.Lorenz at gmail.com wrote: > Hello. > > I am having an issue related to the NDSolve function (I am using > Version 6). The following example illustrates the problem I am > having: > > Input: > sols = NDSolve[{i'[t] == (1/8.516011) (-i[t] + 0.596120754), > i[1] == 0.219319}, i[t], {t, 1, 4}] > > Output: > {{i[t]->InterpolatingFunction[{{1.,4.}},<>][t]}} > > I then would like to solve i[t] for t=3.8 > According to the Mathematica website, I should be able to enter the > following input to receive my answer: > > i[3.8]/.sols > > However, my output is simply i[3.8] and not a numerical value. What > else can I try to get a numerical value from the interpolating > function. > > I appreciate any feedback. Thank you > > >