[Rd] Projects

Saikat DebRoy saikat@stat.wisc.edu
14 Sep 2000 12:27:43 -0500


>>>>> "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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