- To: mathgroup at smc.vnet.net
- Subject: [mg17929] Precision
- From: "Peltio" <peltDOT.ioNOS at PAMiolDOT.it>
- Date: Sat, 5 Jun 1999 02:56:01 -0400
- Organization: Peltio Inc.
- Sender: owner-wri-mathgroup at wolfram.com
Not too long ago , in the Group appeared a message regarding a way to get rid of near zero results due to round off at machine precision. The function f[s_,n_]:= BesselK[0,n(1-s)]-BesselK[0,n]BesselI[0,n(1-s)]/BesselI[0,n] was not giving the expected 0 value for s=0. Somehow, using the Chop function was not useful, even though it resulted in the right series. I was wondering if the following method, that is based on a fast way to rationalize previously suggested in this NG, could represent a viable solution: preciseF[s_,n_]:=f[s,SetPrecision[n,Infinity]] Or is it too demanding from the point of view of the resulting performance? I'm posting this since I did not see further answer to the original post, and all my previous posts got lost due (I think) to my server's problems. Regards, Peltio peltio AT usa DOT net