[Cosmo-torun] isolat-0.1.10.tar.gz ready for testing and comments, feedback

[Boud Roukema]

Witam,
  A GNU GPL (not GNU, just GNU GPL!) package which implements the
algebra in

A Solution to the Isolatitude, Equi-area, Hierarchical Pixel-Coordinate System
http://de.arxiv.org/abs/astro-ph/0409533

is now ready. I've put it here:
http://cosmo.torun.pl/GPLdownload/dodec/isolat-0.1.10.tar.gz

It would be nice to have some precise, constructive comments regarding
this. (Sure, negative criticisms are also welcome, but are most useful
when accompanied by constructive suggestions...)

Today is Mon 8 November.

If there are no objections within a week, i.e. before Mon 15 November,
then i will make a more formal proposal (with deadline two weeks
later) for a formal consensus decision about continued distribution of
the  isolat  package under the GNU GPL.

i realise that this open method of communication means that we give a
chance to "competitors"; however, i think it is best to trust in an
open community. Most of us want to do good, free (as in speech)
astronomy research, so IMHO we should trust our peers. In the long term,
there will be more benefits than problems IMHO.


BTW, just a reminder once again:
http://cosmo.torun.pl/pipermail/cosmo-torun/2004-October/000269.html

Numerical Recipes:
http://www.library.cornell.edu/nr/bookfpdf/f0-1.pdf

; Copyright does not protect ideas, but only the expression of those
; ideas in a particular form. In the case of a computer program, the ideas
; consist of the program's methodology and algorithm, including the
; necessary sequence of steps adopted by the programmer. The expression of
; those ideas is the program source code (particularly any arbitrary or
; stylistic choices embodied in it), its derived object code, and any
; other derivative works.
;
; If you analyze the ideas contained in a program, and then express those
; ideas in your own completely different implementation, then that new
; program implementation belongs to you. That is what we have done for those
; programs in this book that are not entirely of our own devising.

Isolat is *not* based on analysing the ideas in a certain non-free
code which will remain unnamed here, though it *is* based on the
algebraic solution to an electronically published sphere-pixelisation
system.

However, even if it *were* based on analysing the ideas in a certain
non-free code, there would be no copyright problem, since to the best of
my knowledge, the code is a "completely different implementation" to that
non-free code. Of course, it must be more or less equivalent in the basic
"ideas", even though the methodology and algorithm is almost certainly
different, given the way the algebra is written in the paper inspired from
our paper:
http://de.arxiv.org/abs/astro-ph/0409513


Nevertheless, if anybody is concerned about this, please *look at the code*,
don't just rely on rumours of A said that B said that C said that ... . The
code is here:

http://cosmo.torun.pl/GPLdownload/dodec/isolat-0.1.10.tar.gz


The library part of the code is the part which codes the actual
pixel number <-> spherical coordinate
calculations.

There is  lib/getang.f  pixel -> angular coordinates
and  lib/getpix.f  angular coordinates -> pixel
and  lib/fr2pol.f   converts a fraction in the square to phi/pi, sin(th) or inversely

The total number of lines in these three routines, apart from comments
and blank lines can be found by typing:

cat lib/getang.f lib/getpix.f lib/fr2pol.f |grep -v "^[cC]" |grep -v "^$" |wc

It is: 409 lines,   1240 words.

That's not much.

If anyone finds anything in these 409 lines which is considered to be
"an expression (particularly any arbitrary or stylistic choices)" similar
to that in any non-free software package, please say so and we can correct
this.

Simply making vague comments is not going to be constructive. The code is
there and corrections can of course be made: this is the whole idea of GNU GPL,
the idea of coming up with perfect code right from the beginning is not
the way the system works.

pozdr
boud