adehabitat (version 1.8.12)

NNCH.area: LoCoH (NNCH): Home Range Area

Description

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

Usage

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, \dots)

Arguments

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

Value

• NNCH.n.area and NNCH.der.n.area return a data frame of class narea. NNCH.area returns a data frame of class hrsize.

References

Getz, W.M. & Wilmers, C.C. (2004). A local nearest-neighbor convex-hull construction of home ranges and utilization distributions. Ecography, in press.

See Also

NNCH for further information about the NNCH method

Examples

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)