FindRoot question
- To: mathgroup at smc.vnet.net
- Subject: [mg48596] FindRoot question
- From: Jonathan Greenberg <greenberg at ucdavis.edu>
- Date: Sat, 5 Jun 2004 19:58:20 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
I'm using "Rayica", a ray-tracing algorithm for Mathematica, and as part of the calculations it performs it uses FindRoot. I get the following error: FindRoot::lstol: The line search decreased the step size to within tolerance \ specified by AccuracyGoal and PrecisionGoal but was unable to find a \ sufficient decrease in the merit function. You may need more than \ MachinePrecision digits of working precision to meet these tolerances. Can anyone tell me if Mathematica returns a "best guess" if this error occurs, or does it report an error (and no value is returned)? Can I modfiy the tolerance on a global scale (the FindRoot calls are buried in the add-in, so it would be very difficult for me to find them...) --j -- Jonathan Greenberg Graduate Group in Ecology, U.C. Davis http://www.cstars.ucdavis.edu/~jongreen http://www.cstars.ucdavis.edu AIM: jgrn307 or jgrn3007 MSN: jgrn307 at msn.com or jgrn3007 at msn.com