[R] open source and R

[Roger Bivand]

On Sun, 13 Nov 2005, Robert wrote:

> Roger Bivand <Roger.Bivand at nhh.no> wrote: 
> On Sun, 13 Nov 2005, Robert wrote:
> 
> > It uses FORTRAN code and not in pure R.
> 
> The same applies to deldir - it also includes Fortran. So the answer seems 
> to be no, there is no voronoi function only written in R.
> 

Robert wrote:

> 
> I am curious about one thing: since the reason for using r is r is a
> easy-to-learn language and it is good for getting more people involved.
> Why most of the packages written in r use other languages such as
> FORTRAN's code? I understand some functions have already been written in
> other language or it is faster to be implemented in other language. But
> my understanding is if the user does not know that language (for
> example, FORTRAN), the package is still a black box to him because he
> can not improve the package and can not be involved in the development.  
> When I searched the packages of R, I saw many packages with duplicated
> or similar functions. the main difference among them are the different
> functions implemented using other languages, which are always a black
> box to the users. So it is very hard for users to believe the package
> will run something they need, let alone getting involved in the
> development. My comments are not to disregard these efforts. But it is
> good to see the packages written in pure R.
> 

Please indent your replies, they are very difficult to read sensibly.

Although surprisingly much of R is written in R, quite a lot is written in
Fortran and C. One very good reason, apart from efficiency, is code re-use
- BLAS and LAPACK among many others are excellent implementations of what
we need for numerical linear algebra. R is very typical of good scientific
software, it tries to avoid re-implementing functions that are used by the
community, are well-supported by the community, and work. Packages by and
large do the same - if existing software does the required job, package
authors attempt to port that software to R, providing interfaces to
underlying C or Fortran libraries. 

It's about standing on the shoulders of giants.

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no