Re: Gnuastro 0.17.81 released

[Mohammad Akhlaghi]

Hi Peter,

Thanks for the complements on the manual and for doing the checks. Its 
great that we haven't had any crashes so far.

About PGPLOT, as you said, the main problem is that it is not free 
software (others aren't allowed to re-distribute it). So when building 
WCSLIB, we intentionally recommend to add the configuration option to 
disable it in WCSLIB. I personally don't use (as much as possible!), 
encourage or recommend non-free software; and its also a GNU policy ;-).

That appendix on installing it from source is only there for historical 
reasons (because in the early days, I was curious on running it to see 
how it works; and after going through the frustration; I thought those 
notes can be useful to others). But only in the appendix, and not in the 
main body of the text.

DS9 and TOPCAT are in the optional dependencies from package managers, 
because they are used in the 'astscript-fits-view' installed script of 
Gnuastro: it will inspect the contents of the FITS file; if the first 
HDU is an image, it will be opened in DS9, and if its a table, it will 
be opened in TOPCAT. Both are also free software ;-).

Thanks also for the notes on Lzip. I just edited the "Quick start" 
section of the book to focus more on Lzip and avoid the confusions with 
Gzip:

https://git.savannah.gnu.org/cgit/gnuastro.git/commit/?id=bb8f6162f2

As described in the announcement, and in the respective parts of the 
book, Lzip tarballs for software source code have a much better 
compression rate than Gzip. For example for Gnuastro 0.17, the Lzip'd 
tarball was 3.7MB while the Gzip'd tarball was 6.0MB (40% better 
compression). Lzip also uses much more robust archival standards than 
Gzip; and is a far more robust software (if you tried building it from 
source, you will notice how elegantly small it is).

As a result, for alpha releases I only release '.tar.lz', but for main 
releases and for historical reasons, I also put a '.tar.gz' file; but 
still recommend the '.tar.lz' ;-).

Thanks again Peter for the great comments,
Cheers,
Mohammad