From: "M. Edward (Ed) Borasky" <znmeb@...>
Date: 2007-11-13T23:25:46+09:00
Subject: Re: enterprise ruby

Sean Surname wrote:
> M. Edward (Ed) Borasky wrote:
>> GSL doesn't have SVD, least-squares and eigenvalues?
> 
> IIRC GSL has these things (and BLAS and LAPACK), but it lacks others, 
> such as NArray's convenient matrix slice-and-dice syntax.  RSRuby has 
> lots of great statistical routines, but probably can't share data with 
> NArray or GSL.  Each solves its own part of the problem well, but 
> someone still needs to sit down and write efficient (non-copying) and 
> transparent glue between them.  A Matlab transition cheat-sheet would 
> also help (Numpy has one of these).

There is an Octave-to-R cheat sheet available at 
http://cran.r-project.org/doc/contrib/R-and-octave.txt

As far as sharing data is concerned, to keep everybody's garbage 
collectors and memory allocators happy and segfault-free, you probably 
need to do explicit transfers of data between the various packages, 
rather than trying to maintain your sanity and pass pointers at the same 
time. :) Depending on the size of the datasets involved, though, you 
might want to look at something like SQLite files. They're fast, look 
like an RDBMS, and both Ruby and R can talk to them. And if you have 
enough RAM, the OS will buffer them for you. Of course, the datasets I 
deal with are so large I have to put them in PostgreSQL anyhow.