Path: utzoo!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!wuarchive!m.cs.uiuc.edu!joshi
From: joshi@m.cs.uiuc.edu (Anil Joshi)
Newsgroups: comp.lang.c
Subject: Re: Log Library - How is it done in the library code?
Keywords: log, library, series expansion
Message-ID: <1991Mar12.211047.826@m.cs.uiuc.edu>
Date: 12 Mar 91 21:10:47 GMT
References: <1991Mar11.022141.12068@m.cs.uiuc.edu> <15438@smoke.brl.mil> <1991Mar12.014416.4289@m.cs.uiuc.edu>
Organization: University of Illinois, Dept. of Comp. Sci., Urbana, IL
Lines: 32

I got some more responses - some advise and some code.

After going through them I figured out that my initial posting as well as the
followup were not clear enough as to why I want roll my own log.

1. It is a new algorithm to solve LP problems that needs the log to be evaluated
but allows for some lee-way. The convergence rate of the algorithm does not
change on the accuracy of the log function.
2. There is a need to calculate the log function several times over in the 
inner loop of the algorithm.
3. Even if I roll a new log function for this one program, I do not have any
intentions of speeding up of the library function, which won't be easy to do.

All I needed was the info as to what is being done in the library
routine so that I can emulate the library routine. 

In fact, I do know that one cannot write a more efficient routine
than the system supplied one in a short time. That's why I asked
whether the code is available somewhere, so that I can make my
program efficient and fast.

Ironocially, the need to evaluate log has disappeared from the time I posted my
request and now.

So, thanks to all for your advise/code.

Anil
joshi@cs.uiuc.edu
-- 
"Come the (computer) revolution, all persons found guilty of such criminal
behaviour will be summarily executed, and their programs won't be!"
- Press, Flannerty, Teukolsky and Vetterling