| NNCH.area {adehabitat} | R Documentation |
NNCH.area calculates the area of the homerange for different
isopleth levels.
NNCH.k.area for Fixed k LoCoH, computes a data frame containing
the area of the generated homerange vs the value of k used.
NNCH.r.area for Fixed r LoCoH, computes a data frame containing
the area of the generated homerange vs the value of r used.
NNCH.a.area for Adaptive LoCoH, computes a data frame containing
the area of the generated homerange vs the value of a used.
NNCH.n.area computes a data frame containing the area of the
generated homerange vs the variable referenced by n. Called by
NNCH.k.area, NNCH.r.area, and NNCH.a.area.
NNCH.der.n.area computes a data frame containing the derivative
area of the generated homerange vs the variable referenced by n.
Called by NNCH.der.k.area, NNCH.der.r.area, and
NNCH.der.a.area.
NNCH.der.k.area for Fixed k LoCoH, computes a data frame
containing the derivative of the area of the generated homerange vs the
value of k used.
NNCH.der.r.area for Fixed r LoCoH, computes a data frame
containing the derivative of the area of the generated homerange vs the
value of r used.
NNCH.der.a.area for Adaptive LoCoH, computes a data frame
containing the derivative of the area of the generated homerange vs the
value of a used.
plot.narea plots the data frames generated by the above functions
NNCH.area(x, percent = rev(seq(10, 100, by = 10)),
id = NULL, k = NULL, r = NULL, a = NULL, plotit = TRUE)
NNCH.k.area(x, ...)
NNCH.a.area(x, ...)
NNCH.r.area(x, ...)
NNCH.der.k.area(x, ...)
NNCH.der.a.area(x, ...)
NNCH.der.r.area(x, ...)
NNCH.n.area(x, n, percent = c(100,50),
id = NULL, k = NULL, r = NULL, a = NULL)
NNCH.der.n.area(x, n, ...)
## S3 method for class 'narea':
plot(x, ...)
x |
a home range generated using the NNCH() method |
n |
the variable to graph area against; either k, r,
or a |
percent |
the isopleths for which to calculate the area of the home range |
id |
character string specifying a subset of x |
k,r,a |
numeric values specifying a subset of x |
plotit |
logical. Whether the plot should be drawn. |
... |
additional arguments to be passed to the functions |
NNCH.n.area and NNCH.der.n.area return a data frame of
class narea.
NNCH.area returns a data frame of class hrsize.
These functions are useful for determining critical values of
k, r, and a. Big jumps in the the area indicate
that a new chunk of data has been included. Good values of k,
r, and a, usually occur before or after a large jump.
Scott Fortmann-Roe scottfr@gmail.com
Clement Calenge calenge@biomserv.univ-lyon1.fr
Getz, W.M. & Wilmers, C.C. (2004). A local nearest-neighbor convex-hull construction of home ranges and utilization distributions. Ecography, in press.
NNCH for further information about the NNCH
method
## Not run: data(chamois) xy <- chamois$locs ## Try a number of neighbours between 6 and 18 (nn <- NNCH(xy, k = seq(6, 18, by=3))) (i <- NNCH.k.area(nn, percent=100)) plot(i) (i <- NNCH.der.k.area(nn, percent=100)) plot(i) ## Try a number of neighbours between 10 and 15 (nn <- NNCH(xy, k = 10:15)) opar <- par(mfrow=c(1,2)) (i <- NNCH.k.area(nn, percent=100)) plot(i) (i <- NNCH.der.k.area(nn, percent=100)) plot(i) par(opar) ## 12 neighbours seem to be a good choice nn <- NNCH(xy, k = 12) plot(nn) ## End(Not run)