[R-sig-Geo] multitype point patterns

[GodinA]

Hi all,
I have a multitype point patterns representing 12 different species as
follow:

>marked planar point pattern: 821 points 
>multitype, with levels = 88	90	91	92	93	94	96	98	99	100	102	107 
>window: rectangle = [-60, -45] x [40, 56] units 

> head(as.data.frame(skate.ppp))
        x      y         marks
1 -54.198 55.127    88
2 -51.071 43.015    88
3 -47.050 48.111    88
4 -46.377 47.552    88
5 -46.470 47.274    88
6 -51.301 43.041    88

I would like to add another mark with the number of species found at each
location. I'm sure this is fairly straightforward, but somehow I am
struggling with it! I have been doing the following:

>marks(skate.ppp) <- skate$number

However, when I do so, I am replacing all my previous marks by these new
ones... 
> head(as.data.frame(skate.ppp))
        x      y marks
1 -54.198 55.127     2
2 -51.071 43.015     1
3 -47.050 48.111     2
4 -46.377 47.552     1
5 -46.470 47.274     1
6 -51.301 43.041     4

> skate.ppp
marked planar point pattern: 821 points 
marks are numeric, of type ‘double’ 
window: rectangle = [-60, -45] x [40, 56] units  

Thank you very much in advance!
Aurelie


-----
Aurelie Cosandey-Godin
Ph.D. Candidate, Department of Biology
Industrial Graduate Fellow, WWF-Canada

Dalhousie University | Biology Dept. |Halifax, NS, Canada 
Email: godina at dal.ca | Web: wormlab.biology.dal.ca
--------------------------------------------------------------------------
Want to learn more about sharks in Atlantic Canada? Visit ShARCC! www.atlanticsharks.org
--
View this message in context: http://r-sig-geo.2731867.n2.nabble.com/multitype-point-patterns-tp6901052p6901052.html
Sent from the R-sig-geo mailing list archive at Nabble.com.