Dr Weiner has two arguments on that page:

(1) the routines in NR are old and outdated (I imagine most people have the 1992/1996 versions, though the books were updated in 2007)

(2) the NR routines given in the book are copyrighted which means you cannot distribute the source of a code that has NR routines in them to people who do not have the NR license (though you can distribute the

*binary*of the code)

I have never really paid attention to the content copyright pages, so I took a look of my copy of Numerical Recipes to find the following:

...These [diskettes] provide demonstration programs that illustrate the use of each subroutine and procedure in this book. They too can be ordered in the above manner.Now, I am no copyright law professional, but it seems like I can write a code with some functions/subroutines

Unlicensed transfer of Numerical Recipes programs from the abovementioned IBM PC or Apple Macintosh diskettes to any other format, or to any computer except a single IBM PC or Apple Macintosh or compatible for each diskette purchased, is strictly prohibited.

*based*on NR without trouble.

In any event, there are alternatives to Numerical Recipes codes that are more up to date and free. I already mentioned LAPACK at the top of the page, but there is also:

SLATEC -- a large collection of routines such as ODE solvers, numerical integrators, and so on (it was partially re-written in F90 by John Burkardt, see here)

BLAS -- Basic Linear Algebra Subprograms, this is included in the SLATEC package, but is available separately

FGSL -- Fortran interface to the GNU Scientific Library (GSL)

MINPACK -- collection of non-linear equation solvers

I know that some of my colleagues use external libraries (GSL in particular), but I have yet to use any of them. I am somewhat curious about using LAPACK and SLATEC, but I will have to see if I can employ it beyond teaching a lecture or two on it for my class.

I can understand Dr Weiner's argument: why use routines that you have to pay for and are very restrictive in sharing when you can get it free from someone else without any restrictions? And I completely agree, however, I will not be boycotting Numerical Recipes because it is still a fantastic source of information for beginning programmers.

Comments are welcome!

## No comments:

## Post a Comment