41C/CV root finders

[Dieter]

(05-20-2015 07:07 PM)Dave Britten Wrote:  Does anybody have any recommendations for good root finders, or techniques for obtaining initial guesses for i%?

Welcome back to the wonderful world of TVM solvers. ;-) This subject has been discussed here numerous times, including some basic facts that most probably will not change: there is no simple way of getting a decent guess for all possible combinations of the four other TVM variables. Their signs, and even their values, influence the way a first guess for the interest rate may be determined.

Last time this subject has been discussed in December 2014: have look at this thread, especially post #7 and #14 ff.

That thread also includes a link to the old forum where the problems of solving for the interest rate has been discussed in detail, even with graphs showing different scenarios and their special problems. Here is a link.

I fear things haven't changed much since then. ;-)

Dieter