[GRASS5] TODOs for 5.0.0

Markus Neteler neteler at itc.it
Fri Aug 31 11:44:15 EDT 2001


One more comment,

On Thu, Aug 09, 2001 at 12:56:43PM +0100, Glynn Clements wrote:
[...]
> + rand1 - Used by r.surf.fractal, r.surf.gauss, r.surf.random.
> 
> Free PRNGs are readily available; the most obvious candidates are:
> 
> 1. The ANSI C rand() and srand() functions.
> 2. The BSD random() and srandom() functions.
> 
> 1 is available on all platforms, but some implementations have poor
> entropy.
> 
> 2 may not be available on all platforms; it is available in BSD4.3
> onwards, and in GNU libc. If it isn't available, 1 could be used
> instead. Alternatively, the code could be taken from GNU libc.

My colleague recommends drand48() - maybe not surprising for you.
I don't know too much about this stuff.

Please keep in mind that drand48() is lacking on Cygwin and MacOSX,
compare for a workaround:
src/raster/r.mapcalc/mapcalc/xrand.c

Markus



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