Re: How to treat this false singular point?

*To*: mathgroup at smc.vnet.net*Subject*: [mg68408] Re: [mg68406] How to treat this false singular point?*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Fri, 4 Aug 2006 03:59:21 -0400 (EDT)*Reply-to*: hanlonr at cox.net*Sender*: owner-wri-mathgroup at wolfram.com

f[x_, xList_List] := Total[(x-xList)*Log[Abs[x-xList]]]; f[x, {x1, x2, x3}] (x - x1)*Log[Abs[x - x1]] + (x - x2)*Log[Abs[x - x2]] + (x - x3)*Log[Abs[x - x3]] a singularity will exist for each value of x in xList; therefor, f[xn, xList] cannot have the value 1 f[5. - 10^-15, Range[5]] 10.2273 Plot[f[x,Range[5]],{x,-1,5}]; Bob Hanlon ---- simon yang <yanshanguke at 163.com> wrote: > Dear everyone, > I have a function: > f[x_]:=(x-x1)Log[Abs[x-x1]] + (x-x2)Log[Abs[x-x2]] + ... + > (x-xn)Log[Abs[x-xn]], > {x1,x2,...,xn}={100,200,300,...} for instance > How to get value: f[x] as there are different singular at different x? > I know at x=xn, f[x]==1, But Mathematica return: "Indeterminate", What > should I do? > what others do in C++, Fortran ? >