[Rd] Projects

[A.J. Rossini]

(not to the list)

>>>>> "PG" == Paul Gilbert <pgilbert@bank-banque-canada.ca> writes:

    DM> Putting that into a single function which took arguments just
    DM> like the ones you pass to the optimizer would be very
    DM> convenient.

    >> That's exactly it.  (but perhaps have at least the 3 basic
    >> forms -- f(point + eps) - f(point), f(point + eps/2) - f(point
    >> - eps/2), f(point) - f(point - eps)).

    PG> Buried somewhere in one of my packages is code for doing
    PG> Richardson extrapolation, which usually gives a much better
    PG> estimate than these 3 basic forms. If this project goes ahead
    PG> I will dig it out.

That would be cool, and I believe there are other, more precise,
approaches!  BUT, I'm worried that this (_numerical_ derivatives),
might become a package unto itself (which gets amusing, especially if
you consider the many ways one might want to differentiate a
multi-array vector by a vector...).

All of a sudden, I'm starting to see 2 projects out of one, depending
on the scope.

-- 
A.J. Rossini				Rsrch. Asst. Prof. of Biostatistics
BlindGlobe Networks (home/default)	rossini@blindglobe.net	
UW Biostat/Center for AIDS Research	rossini@u.washington.edu	
FHCRC/SCHARP/HIV Vaccine Trials Net	rossini@scharp.org

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