If your function has nice derivatives, you may want to look at the Newton implementation in

http://hackage.haskell.org/packages/archive/ad/0.44.4/doc/html/Numeric-AD-Newton.html#v:findZero

or if you have enough derivatives, you can even move up to the next Householder method at Numeric.AD.Halley.findZero

These have the benefit of using exact derivatives, and returning a stream of successively better approximations.

-Edward


On Fri, Mar 18, 2011 at 7:39 PM, Artyom Kazak <artyom.kazak@gmail.com> wrote:

Hi Café!

roots (http://hackage.haskell.org/package/roots) is a package to solve equations like "f(x)==0".

In RootFinder class there is an 'defaultNSteps' value, which is used as maximal count of iterations functions like findRoot and traceRoot can make. By default it is 250, but sometimes it's not enough. How can I use another value instead of 250? Should I write my own RootFinder instance, or findRoot function?

Thanks in advance.
— Artyom.

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