Re: Using "If" and "NDSolve" together

*To*: mathgroup at smc.vnet.net*Subject*: [mg106859] Re: Using "If" and "NDSolve" together*From*: RBenf <rui.benfeitas at gmail.com>*Date*: Mon, 25 Jan 2010 05:07:15 -0500 (EST)

Hello Bobby, thanks for all the help! It was good to see how you can simplify what I wrote into just a few coding lines. I'm still learning how to work with Mathematica, and from what I've seen, it will still be a long way until I can use it effectively. Although the code that you gave me does not do exactly what I want to do, I will surely use it in order to solve my problem. Thanks a lot! > Oh, what a tangled web you weave. > > Clear[funcao] > funcao[first_, last_] := > Module[{k0 = 10^-2, k1 = 10^-5, k2 = 10^-6, k3 = > = 10, a, b, c}, > a = a /. First@ > NDSolve[{a'[t] == k0 Boole[first <= t <= last] > last] - k1 a[t], > b'[t] == k1 a[t] - k2 b[t], c'[t] == k2 b[t] > k2 b[t] - k3 c[t], > a[0] == 2 10^-6, b[0] == 0, c[0] == 0}, {a, > 0}, {a, b, c}, {t, 0, > 1000}]; > Plot[a@t, {t, 0, 1000}, PlotRange -> All] > ] > funcao[0, 100] > funcao[0, 900] > funcao[100, 900] > > Bobby