[GRASS5] g51 v.build accelerated

Markus Neteler neteler at itc.it
Mon Feb 18 02:43:30 EST 2002

On Mon, Feb 18, 2002 at 08:18:53AM +0100, Andrea Aime wrote:
> Radim Blazek wrote:
> > 
> > v.build accelerated now:
> > 
> > grass50  grass51
> > 270s     9s     (with attributes)
> > 124s     6s     (without attributes)
> > 
> > How boring. Somebody should check, seems to be too good.
> > 
> Mmm, I haven't looked at the new code, but the old
> version uses a hand made realloc that allocates a new
> array and then copies the old array into the new 
> element by element, thus making
> lots of works each time an array has to be enlarged
> (according to the few comments available realloc was
> buggy on Solaris at the time v.build was written) ...
> maybe your new implementation uses the standard libc 
> realloc, which is much faster than this... just a guess
> (maybe I am completely wrong)
> ciao
> Andrea Aime

Ciao Andrea,

is your comment a hint how to speed up the v.build in 5.0? :-)
That would be really great. To build topology for the GSHHS shoreline
data takes more than 2 days on an average machine (o.k., yes, it is
possible and not crashing as seen with market place GIS software).


More information about the grass-dev mailing list