From Martin Maechler <maechler@stat.math.ethz.ch>  Thu Sep 14 17:46:41 2000
From: Martin Maechler <maechler@stat.math.ethz.ch> (Martin Maechler)
Date: Thu, 14 Sep 2000 18:46:41 +0200
Subject: [Rd] Projects
In-Reply-To: <6rk8cfkmru.fsf@franz.stat.wisc.edu>
References: <6rk8cfkmru.fsf@franz.stat.wisc.edu>
Message-ID: <14785.241.670605.528570@gargle.gargle.HOWL>


1) Design of Experiments :

 - S (even before "-plus" existed) has had functions like

   fac.design
   oa.design
   fractionate   etc  ["White book", chapter 5].

		 [also a set of pre-stored useful fractional designs
		  for (> 2)-leveled factors.]

  Some of these would look like ``student exercises'' to do.
  If you could have them work in an environment where S-plus was *not*
  installed, this would end up as "clean table" project 
  w/o problematic code copying...

 - One could also think of  code for SEQUENTIAL design
  [do a  2^{m-k} (= 8) initially; 
   do a  (fractionated) n1 x .. x n_N on the remaining N important factors,
   given the data for the first 8 experiments].

 - Or "Taguchi" [- using (at least two) different kind of factors, some cheap,
		   some expensive to change
		 - multiple Y's, for some the "local" variance should be
		   minimized, etc etc
		 ]
	      
  This looks tedious and maybe can well be partitioned into different student
  projects.  Maybe JMC, AEF, RMH (authors of ch.5) or other experts can say
  much more here.

------

2) For Computer Scientists :
    "Differentiation" / Symbolic derivatives,..

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

   Think about the hessian in addition to the gradient.

  

--------

Martin Maechler <maechler@stat.math.ethz.ch>	http://stat.ethz.ch/~maechler/
Seminar fuer Statistik, ETH-Zentrum  LEO D10	Leonhardstr. 27
ETH (Federal Inst. Technology)	8092 Zurich	SWITZERLAND
phone: x-41-1-632-3408		fax: ...-1228			<><
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[Rd] Projects
Martin Maechler