density /diversity of points
Hi all, I can not for the life of me find out how to covert this : plot(eval.im(mol.simpson.s >0.3 & (mol.den/max(mol.den))>0.3)) into any kind of grid or shape with projection that can be used in some GIS software. Any help is greatly appreciated. m -----Original Message----- From: r-sig-geo-bounces at r-project.org [mailto:r-sig-geo-bounces at r-project.org] On Behalf Of Mathieu Rajerison Sent: Wednesday, May 18, 2011 8:34 AM To: r-sig-geo at r-project.org Subject: Re: [R-sig-Geo] density /diversity of points Yes, you're totally right about the name of the objects :) So, setting exclude=FALSE is necessary if one wishes to include the point itself in the marktable function and there is no zero values, at least one "1" clc.tab<-marktable(clc.ppp, R=20, exclude=FALSE) To get the minimal radius for which a neighbor is found, I simply used nndist function min(nndist(clc.ppp)) Finally, I decided to set a 2000 units radius and to include the radius starting point clc.tab<-marktable(clc.ppp, R=2000, exclude=FALSE) I get good results Thanks everybody for everything! 2011/5/17 Rolf Turner <r.turner at auckland.ac.nz>
On 18/05/11 05:05, Mathieu Rajerison wrote:
I've tried your method to determine the richness of landscapes on my area of interest using european corine land cover. I converted my polygon layer into a SpatialGridDataFrame then into a SpatialPointsDataFrame, and finally into a ppp object using one column: the type of soil occupation (CLC3_LIB). But my problem is that marktable gives me zero values, although I should get at least a "1" value for one of my columns... Here is a sample code:
ppp[1:5]$marks
[1] Mer et oc?an [2] V?g?tation clairsem?e [3] Pelouses et p?turages naturels [4] V?g?tation scl?rophylle (y.c. maquis et garrigue) [5] V?g?tation scl?rophylle (y.c. maquis et garrigue) marktable(ppp[1:10], R=50)
mark
point A?roports Chantiers Cours et voie d'eau
1 0 0 0
2 0 0 0
3 0 0 0
4 0 0 0
5 0 0 0
6 0 0 0
7 0 0 0
8 0 0 0
9 0 0 0
10 0 0 0
mark
point Equipements sportifs et de loisirs
1 0
2 0
3 0
4 0
5 0
6 0
7 0
8 0
9 0
10 0
I don't see where the problem is..
Any help would be greatly appreciated.
Why do you assert that you should get at least one "1"? If there are
no points of your pattern within 50 units of any given point, then the
table will indeed consist of nothing but zeros.
If you don't believe that this is the problem then please provide a
minimal
***reproducible*** example that we can work with, as the posting guide
requests.
And ***PLEASE*** do not call your point pattern "ppp"; this is the
name of a function and class in the spatstat package. Using it as the
name of an object is very confusing and potentially a source of
errors. See fortune("dog").
cheers,
Rolf Turner