clusthr {adehabitatHR}  R Documentation 
Estimation of the Home Range by SingleLinkage Cluster Analysis
Description
clusthr
allows the estimation of the home range by
singlelinkage cluster analysis (see details).
Usage
clusthr(xy, unin = c("m", "km"),
unout = c("ha", "m2", "km2"),
duplicates=c("random","remove"), amount = NULL)
Arguments
xy 
an object inheriting the class 
unin 
the units of the relocations coordinates. Either

unout 
the units of the output areas. Either 
duplicates 
a setting to determine how duplicated points are
handled. If " 
amount 
if 
Details
This method estimates home range using the singlelinkage cluster analysis modified by Kenward et al. (2001). The clustering process is described hereafter: the three locations with the minimum mean of nearestneighbour joining distances (NNJD) form the first cluster. At each step, two distances are computed: (i) the minimum mean NNJD between three locations (which corresponds to the next potential cluster) and (ii) the minimum of the NNJD between a cluster "c" and the closest location. If (i) is smaller that (ii), another cluster is defined with these three locations. If (ii) is smaller than (i), the cluster "c" gains a new location. If this new location belong to another cluster, the two cluster fuses. The process stop when all relocations are assigned to the same cluster.
At each step of the clustering process, the proportion of all relocations which are assigned to a cluster is computed (so that the home range can be defined to enclose a given proportion of the relocations at hand, i.e. to an uncomplete process). At a given step, the home range is defined as the set of minimum convex polygon enclosing the relocations in the clusters.
Note that a given homerange contour can be extracted using the
function getverticeshr
.
Value
The function clusthr
returns either objects of class
SpatialPolygonsDataFrame
(if the relocations of only one
animals are passed as the xy
argument) or a list of
SpatialPolygonsDataFrame
of class MCHu
– Multiple
Convex Hull (if the relocations of several animals are passed as the
xy
argument).
Author(s)
Clement Calenge clement.calenge@ofb.gouv.fr
References
Kenwward R.E., Clarke R.T., Hodder K.H. and Walls S.S. (2001) Density and linkage estimators of homre range: nearest neighbor clustering defines multinuclear cores. Ecology, 82, 1905–1920.
See Also
MCHu
for further information on the class
MCHu
, and SpatialPolygonsDataFrameclass
for
additional information on this class. See getverticeshr
to extract a given home range contour.
Examples
data(puechabonsp)
lo<puechabonsp$relocs[,1]
## Home Range Estimation
res < clusthr(lo)
## Displays the home range
plot(res)
## Computes the home range size
MCHu2hrsize(res)
## get the 95 percent home range:
plot(getverticeshr(res, percent=95))