[GRASS5] r.le in GRASS-5?

Roger Bivand Roger.Bivand at nhh.no
Fri Jul 6 05:38:43 EDT 2001

On Thu, 5 Jul 2001, Eric G. Miller wrote:

> On Thu, Jul 05, 2001 at 05:20:35PM +0000, Michel Wurtz wrote:
> > Markus Neteler wrote:
> > > 
> > And one more time, it's a null file related problem... It seems that a
> > good null values management is becomming an urgent need.
> > BTW, nobody commented my last proposal, which either means that everybody
> > agrees or that I'm way off out out of topic ;-)
> I certainly don't think it gets any simpler if you move the
> handling of the NULL representation to outside of libgis,   
> or if the values are embedded.  Your modules still have to be prepared
> to handle NULL, and NULL could be anything, so use G_is_null_value().
> I don't see anything particularly wrong with wanting to embed NULL
> values, but I certainly don't feel like diving into that raster code
> again.  It isn't broken.  Lots of other things are.  Is GRASS 5.0 ever
> going to get released?  Leave it for 5.1.  It's just too dangerous to be
> mucking in that territory if GRASS 5.0 is ever going to be released
> before the next millenium.
I think Eric is quite right. Leave changing the NULL functions until
5.1. We simply don't know how or which programs or functions use the NULL
API correctly for a simple replacement of NULL handling to be feasible. Of
course the present mechanism is an unsatisfactory hack, but it does work,
except when users don't know that 0 can be a missing data value.


Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Breiviksveien 40, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 93 93
e-mail: Roger.Bivand at nhh.no
and: Department of Geography and Regional Development, University of
Gdansk, al. Mar. J. Pilsudskiego 46, PL-81 378 Gdynia, Poland.

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