Re: Q
- To: mathgroup at smc.vnet.net
- Subject: [mg41405] Re: [mg41390] Q
- From: Selwyn Hollis <selwynh at earthlink.net>
- Date: Sun, 18 May 2003 05:02:43 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Though there's probably a Mathematica-ally slicker way, the following will work (and I beg forgiveness for the Do loop!): n=4; derivs = Join[{f[t]}, Table[D[F[f[t]],{t,k}], {k,0,n}]]//. {t->0, f[0]->f0}; Do[fk = D[f[t], {t,k}]/. t->0; derivs = derivs /. fk->derivs[[k+1]], {k,1,n}]; derivs [reference/plug: A Mathematica Companion for Differential Equations, by me.] ----- Selwyn Hollis http://www.math.armstrong.edu/faculty/hollis On Saturday, May 17, 2003, at 05:50 AM, Stepan Yakovenko wrote: > HI! > > I've got an equation f'[t]=F[f[t]]. > F[] is known and analytic, (say > F[x]=x*x). I know f[0]=f0. f0 is > a number. I want to get all f'[0], > f''[0], f'''[0], ... assigned > to their numberical values that can be > unambiguously found after differentiating > the source equation as many times as > needed. > > > -- > Try "win /t" to run Windows in text mode > > >