[GRASSLIST:4652] RE:Two questions: 1. r.param.scale; usage and etc... an error got into my last post!!

[Markus Neteler]

On Sat, Sep 14, 2002 at 12:07:53AM +0200, Lars Forseth wrote:
> On Thursday 12 September 2002 08:22, Markus Neteler wrote:
> > I think that r.param.scale was updated *after* we wrote that section.
> > That means that the default values are different, maybe leading to bad
> > results with integer DEM. I will investigate after GRASS conference.
> >
> > > (By the way a good book :-)!)
> > >
> > > 2. Is there a way you can to a "density" analysis a la ArcView
> > > SpatialAnalyst; with sites (i e point) data? How?
> >
> > The s.kernel is close to be released. It seems to do it's job :-)
> > But: could you write in detail what SpatialAnalyst is doing when doing
> > "density" analysis?
> >
> > Markus
> 
> Markus and others!
> 
> Sorry for a little late response to this, but I am doing this list from my 
> home using my private e-mail adress.
> 
> Enclosed you will find a t.xt file with the text from the relevant help 
> section in ArcView 3.2 with SpAnalyst v 2.0 installed. I think Erik G Miller 
> is pretty accurate in his response on this. Though it does allow you to 
> choose betwen simple and kernel density type. And it also calculates the 
> density based on a circle, the diameter of witch you give as a parameter. In 
> "The ESRI guide to GIS analysis" vol 1: p 75-85 describe the methodolgy 
> behind density surfaces in SA.  
> 
> The s.kernel module sounds to be pretty much what I am looking for. 

... thanks to Stefano Menegon from ITC-irst it is in CVS now....

Src code:
http://freegis.org/cgi-bin/viewcvs.cgi/grass/src/sites/s.kernel/s.kernel.tar.gz?tarball=1

HTML page (not yet very chatty):
http://freegis.org/cgi-bin/viewcvs.cgi/*checkout*/grass/html/html/s.kernel.html?rev=1.1

Probably s.kernel will be improved in future. Suggestions/patches welcome.

Cheers

 Markus