I read Ihaka's paper a while ago (so I apologize for my faulty memory)
and iirc he is interested in reimplementing R in Lisp in order to
make it run faster. I was kind of puzzled by the that. Obviously (well, it's
obvious to me anyway) the big payoff is to combine numerical and symbolic
computations.
I would be very interested in porting some R capabilities into Maxima.
I made a half-hearted effort to implement a "data frame" construct.
I guess I should finish it.
Another statistical package that could benefit from combined
symbolic & numerical computations is the Bayesian inference
package BUGS. I made some progress (far from a complete implementation)
of a scheme to attempt symbolic computation first and then fall
back on a numerical scheme. (The calculations of interest are integrals.)
I wrote a paper about that if you're interested.
I'd be interested to hear yours or anyones thoughts about this stuff.
best, Robert Dodier