Re: Higher precision in Error function Erf[] needed.

*To*: mathgroup at smc.vnet.net*Subject*: [mg127141] Re: Higher precision in Error function Erf[] needed.*From*: "Nasser M. Abbasi" <nma at 12000.org>*Date*: Mon, 2 Jul 2012 05:26:41 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <jsbt4i$6pq$1@smc.vnet.net> <jseeua$i3d$1@smc.vnet.net> <jsjqhg$d2j$1@smc.vnet.net> <jsmg81$1jj$1@smc.vnet.net>*Reply-to*: nma at 12000.org

On 6/30/2012 4:17 AM, Ray Koopman wrote: > > Just alter the precision of its input. First define > > f[x_,n_] := 8*(10 - Abs[10 - 20000*SetPrecision[x,n]]) > > Then > > Plot[Exp@#*(1-Erf@Sqrt@#)&@f[x,20], {x,0,10^-3}, Compiled->False] > > works fine. > fyi; using Mathematica 8, the 'Compiled->False' is shown in RED letters, meaning is not valid option for Plot. on a side note, I myself, and this is just a styling thing, when using pure function, find it easier to use @ for only the RHS of the pure function. Hence the above command would become Plot[ Exp[#] * (1-Erf[Sqrt[#]])& @f[x,20], {x,0,10^-3}] vs. Plot[Exp@# * (1-Erf@Sqrt@#)& @f[x,20], {x,0,10^-3}] Again, just different styling, all is valid, but for me, I find the first case above a little easier to read, since @ is used only for the pure function argument. regards, --Nasser