Berkeley CSUA MOTD:Entry 10391
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2025/05/24 [General] UID:1000 Activity:popular
5/24    

2003/10/1 [Computer/SW/Security, Computer/SW/Unix] UID:10391 Activity:nil
9/30    I'm not a very mathy person, but I've found myself in dire need of
        a good root-finding algorithm.  I've currently got a piece of
        software that uses Mueller's Method -- but it sometimes generates
        whack results that crash a rather twitchy third party piece of
        software as it iterates.  The curves I'm examining can be assumed to
        be monotonic.  Can I do better than Mueller's, or am I SOL?  TIA. -mice
        \_ Use Mathworld to look up 'root finding' and find the root finding
           method which will work best for the kind of function you have.
           Using mathworld for this sort of thing is a good meta-skill to learn.
        \_ you'd probably find a numerical analysis text more useful than
           mathworld. try checking one out at a college library if you can.
           there are not that many root-finding methods that are actually
           used much in real life.
        \_ One technique to explore-- see if you can parameterize your
           curve on some region of interest by a [0,1] lambda.  I.e.. munge
           your algebra around until you can get a diff from root as a
           function of some linear parameter.  If your curve is nice,
           consider golden section or binary search.  Another thing to do
           is just chop up lambda into increments, evaluate diff, and
           pick the best guess at root (or refine search in a region of
           the best approx from a linear visit across lambda).  Not the
           niftiest method in the universe, but it gets the job done.
2025/05/24 [General] UID:1000 Activity:popular
5/24    

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