mcp {adehabitat} | R Documentation

## Estimation of the Home Range Using the Minimum Convex Polygon Estimator

### Description

`mcp` computes the home range of several animals using the minimum convex polygon estimator.
`mcp.area` is used for home-range size estimation. This function requires the package `gpclib`.
`plot.hrsize` is used to display the home-range size estimated at various levels.

### Usage

    mcp(xy, id, percent = 95)
    mcp.area(xy, id, percent = seq(20,95, by=5),
             unin = c("m", "km"),
             unout = c("ha", "km2", "m2"))
    plot.hrsize(x, ...)

### Arguments

`xy` | a data frame containing the coordinates of the relocation of the monitored animals
`id` | a factor giving the identity of the animal for each relocation
`percent` | 100 minus the proportion of outliers to be excluded from the computation
`unin` | the units of the relocations coordinates. Either `"m"` (default) for meters or `"km"` for kilometers
`unout` | the units of the output areas. Either `"m2"` for square meters, `"km2"` for square kilometers or `"ha"` for hectares (default)
`x` | an objet of class `hrsize` returned by the function `mcp.area`, or `kernel.area` (see the help page of this function)
`...` | additionnal arguments to be passed to the function `plot`

### Details

This function computes the Minimum Convex Polygon estimation after the removal of `(100 minus percent)` percent of the relocations the farthest away from the barycenter of the home range (computed by the arithmetic mean of the coordinates of the relocations for each animal).

### Value

`mcp` returns an object of class `area`, with one polygon per level of the factor ID.
`mcp.area` returns a data frame of class `hrsize`, with one column per animal and one row per level of estimation of the home range

### Author(s)

Clément Calenge calenge@biomserv.univ-lyon1.fr

### References

Mohr, C.O. (1947) Table of equivalent populations of north american small mammals. The American Midland Naturalist, 37, 223-249.

### See Also

`chull`, `plot.area` to have a graphical display of the home ranges, `as.area` for additionnal information on the class `area`, and `area2dxf` for further exportation toward a GIS. `s.chull` for another way to display MCP

### Examples

    data(puechabon)
    locs <-  puechabon$locs

    cp <- mcp(locs[,4:5], locs[,1])

    ## Plot the home ranges
    opar <- par(mar = c(0,0,0,0))
    area.plot(cp)

    ## ... And the relocations
    points(locs[,4:5], pch = 16, col = as.numeric(locs[,1]))
    par(opar)

    ## Computation of the home-range size:
    if (require(gpclib)) {
      (cuicui1 <- mcp.area(locs[,4:5], locs[,1]))
      plot(cuicui1)
    }

[Package adehabitat version 1.4 Index]