🚀 go-pugleaf

Vadim Tarassov <vadim@pci.unizh.ch> writes:

> Hi, Ken
> 
> Now try your best, force yourself to concentrate your attention on
> following point.
> Ok, one ... two ... three ...
> Don't you think that routine was tested before published?

If they did test their routines rigorously I would like to see them
publish a test suite. (I know they did publish "examples" but I don't
know that they published a rigorous test suite)

Also, if you concetrate your attention as well, you might remember that there
are those things called "bugs". They kinda find their way into programs,
and users running into them report them to Pest Control to get the code
debugged. The Numerical Recipies publishes newer versions of their
library every once in a while for this reason. They say that the bugs
become resistent to the insecticides, which is why these bugs just
keep coming back.

Finally, it is important to note that numerical recipies are not free
software, so it is not appropriate to discuss them in gnu.misc.discuss,
unless you want to discuss the nature of their license terms. 
If you write a program that depends on numerical recipies routines
you can not legally redistribute these routines. This is particularly
onerous if you want your program to be free software, or if you need to
_modify_ their routines. 

In general be very cautious of books with published source code. Always 
review the copyright status of their code before using it in projects that 
you might want to share with your collegues. In almost all cases that I know 
of, such books give you no rights. The copyright terms are always stated 
behind the book's titlepage. In Numerical Recipies, you are granted
a License which is discussed in an unnumbered section in the beginning
of the book. That License is extremely restrictive however. If no permissions
or License are mentioned, this means that you are given no rights at all.
In that case, it might even be illegal to copy the source code from the book 
to your computer by hand. This is very sad because, as far as I am 
concerned it makes a big chunk of these books useless to me.

Elef.


> 
> Ken Laberteaux wrote:
> 
> > I am reading the 2nd Edition of _Numerical Recipes in C_.  I am
> > specifically looking at laguer.c.
> >
> > On p. 373 the line of code which implements Eq 9.5.7 (p. 372) is
> >
> >                h=Csub(g2,RCmul(2.0,Cdiv(f,b)));
> >
> > However Eq 9.5.7 (p. 372) makes no reference of the 2, indicating that
> > the correct version should be
> >
> >                h=Csub(g2,Cdiv(f,b));
> >
> > Can anyone shed some light into this inconsistency?
> >
> > Ken Laberteaux