From saikat@stat.wisc.edu  Thu Sep 14 18:27:43 2000
From: saikat@stat.wisc.edu (Saikat DebRoy)
Date: 14 Sep 2000 12:27:43 -0500
Subject: [Rd] Projects
In-Reply-To: rossini@blindglobe.net's message of "14 Sep 2000 09:52:48 -0700"
References: <6rk8cfkmru.fsf@franz.stat.wisc.edu> <14785.241.670605.528570@gargle.gargle.HOWL> <873dj2ncf3.fsf@jeeves.blindglobe.net>
Message-ID: <qxpaeda6fzk.fsf@verdi.stat.wisc.edu>

>>>>> "AJR" == A J Rossini <rossini@blindglobe.net> writes:

>>>>> "MM" == Martin Maechler <maechler@stat.math.ethz.ch> writes:
  MM> 2) For Computer Scientists : "Differentiation" / Symbolic
  MM> derivatives,..

  MM> Improve the possibilities of D() and deriv(), and document them.
  MM> Make these user-extensible.

  MM> Think about the hessian in addition to the gradient.

  AJR> Even automating/specifications for numerical derivatives would
  AJR> be nice.

The nls package has a function called numericDeriv - with a little
modification it could be used elsewhere. An earlier version of the
underlying C code is used as an example in the R Extensions manual.

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[Rd] Projects
Saikat DebRoy