14 Sep 2000 20:26:33 -0700
>>>>> "DM" == Duncan Murdoch <email@example.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
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
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