Linux sort doesn't work with negative float numbers

All those troubles did my local settings. My ubuntu is in Czech:

$ echo $LANG
cs_CZ.UTF-8

In this local setting it's not a decimal point, rather a decimal comma that seperates integer from the rest (as we were thought in math classes, in our language we really do write comma instead of a point).

Therefore:

echo '0,03 >> 0,4 >
> -0,3 >
> 0' | sort -n
> 0
> -0,3 >
> 0,4 >
0,03 >

If you are writing a bash script, set the sorting routine to use the "normal" settings.

export LC_ALL=C

The problem may be in your sort command. If I run the same my result is as expected:

$ echo '0.00159265291648695254
> -0.00318530179313823899
> 0
> 0.00999983333416666468
> 0.00362937767285478371
> 0.00477794259012844049
> -0.00637057126765263261
> 0.00681464007477014026
> -0.00840724736714870645
> -0.00522201549675090458' | sort -n
-0.00840724736714870645
-0.00637057126765263261
-0.00522201549675090458
-0.00318530179313823899
0
0.00159265291648695254
0.00362937767285478371
0.00477794259012844049
0.00681464007477014026
0.00999983333416666468

You shoud use GNU sort if not using it

sort (GNU coreutils) 5.93
Copyright (C) 2005 Free Software Foundation, Inc.
This is free software.  You may redistribute copies of it under the terms of
the GNU General Public License <http://www.gnu.org/licenses/gpl.html>.
There is NO WARRANTY, to the extent permitted by law.

Written by Mike Haertel and Paul Eggert.