[Rd] Projects

A.J. Rossini rossini@blindglobe.net
14 Sep 2000 20:26:33 -0700

>>>>> "DM" == Duncan Murdoch <dmurdoch@pair.com> writes:

    DM> On 14 Sep 2000 10:43:05 -0700, you wrote:
    >> Right, and it would be nice (necessary?) for testing and
    >> verification of the "symbolic" side of the package as well as
    >> for "drop-in" or "change a parameter" design functionality.  As
    >> well as being a starting point for the interface for the
    >> symbolicDeriv package.

    DM> I'm not sure if this is what Tony has in mind, but something I
    DM> always do when working with optimizers that take a supplied
    DM> derivative is to write a little numerical derivative routine
    DM> to check that my calculus and programming were done correctly.
    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)).


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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