[GRASS5] [bug #4045] (grass) r.random not so random

[Hamish]

> this bug's URL: http://intevation.de/rt/webrt?serial_num=4045
> ---------------------------------------------------------------------
> 
> Subject: r.random not so random
> 
> Platform: WindowsNT/2000/XP
> grass obtained from: Other (CDROM etc)
> grass binary for platform: Downloaded precompiled Binaries
> GRASS Version: 6.0.0
> 
> I recently downloaded and installed the cygwin version of GRASS GIS. 
> My primary objective is to generate hillshades.  To do so I have been
> importing shapefiles with contour data and running v.surf.rst.  The
> results have been OK but very segmented. Following the suggestion by
> Neteler and Mitasova in "Open Source GIS: A GRASS Approach", I
> attempted to generate random points to merge with the contour points
> and re-run v.surf.rst.  Unfortunately, r.random seems to be generating
> points clustered at the top of the region. I have been unable to find
> a way around this in GRASS and have noticed only one or two mentions
> of the problem in the mailing list archives, but no suggested
> work-around.
> 
> Request: The randomness of r.random requires improvement/correction.


Can you try GRASS 6.1? I think it is fixed.

here we go:

http://freegis.org/cgi-bin/viewcvs.cgi/grass6/raster/r.random/creat_rand.c

Revision 2.1 / (as text) / (view) - annotate - [select for diffs] , Tue Jul 5 05:50:31 2005 UTC (6 months, 3 weeks ago) by hamish
Branch: MAIN
Changes since 2.0: +1 -1 lines
Diff to previous 2.0

fix lrand48() for Cygwin & Apple. (fix from Glynn)  see:
  http://grass.itc.it/pipermail/grass5/2005-June/018519.html
  http://grass.itc.it/pipermail/grass5/2005-June/018528.html


.. but apparently not backported to 6.0.x. 
  (can someone please do if it works?, thanks.)



Hamish