> >>>>> "bry" == bry <[EMAIL PROTECTED]> >>>>>> on Fri, 15 Jul 2005 14:16:46 +0200 writes: > > bry> About a year ago there was a discussion about interfacing R >with J on the J > bry> forum, the best method seemed to be that outlined in this >vector article > bry> http://www.vector.org.uk/archive/v194/finn194.htm > >(which is interesting to see for me, > if I had known that my posted functions would make it to an APL > workshop... > BTW: Does one need special plugins / fonts to properly view > the APL symbols ? ) > > > bry> and use J instead of APL > > bry> http://www.jsoftware.com > >well, I've learned about J as the ASCII-variant of APL, and APL >used to be my first `beloved' computer language (in high school!) >-- but does J really provide computer algebra in the sense of >Maxima , Maple or yacas... ??
I wonder if at this point it would be useful to think about how a symbolic algebra system might be used by R users, and whether that would affect the choice of system. For example, Maxima and yacas seem to be mostly concerned with "getting the job done", which might be all that the data analyst or occasional user needs. However, mathematical statisticians might be more concerned with developing new mathematics. For example, commutative algebra has been found to be very useful in the theory of experimental design (e.g. Pistone, Riccomagno, Wynn (2000) Algebraic Statistics: Computational Commutative Algebra in Statistics. Chapman & Hall). Now, Maxima can already do the necessary calculations (ie Groebner bases of polynomials), but as far as I know, yacas cannot. But who knows where the next breakthrough will come from? In that case Axiom might be more useful and appropriate, as it is largely used by research mathematicians. We would then need a mechanism for the development of new data structures in R that could potentially match Axiom's rich and extensible type system. I guess some mechanism that relies on S4 classes would be necessary. Of course, there is nothing to stop us developing packages for more than one system ("We are R. We will assimilate you!"). I have no idea how to do any of this: I'm just floating ideas here. :-) Cheers, Simon. > >(and no, please refrain from flame wars about APL vs .. vs .., > it's hard to refrain for me, too...) > >Martin Maechler, ETH Zurich > >______________________________________________ >R-devel@r-project.org mailing list >https://stat.ethz.ch/mailman/listinfo/r-devel -- Simon Blomberg, B.Sc.(Hons.), Ph.D, M.App.Stat. Centre for Resource and Environmental Studies The Australian National University Canberra ACT 0200 Australia T: +61 2 6125 7800 F: +61 2 6125 0757 CRICOS Provider # 00120C ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel