count.points.id: Number of Points in Each Pixel of a Raster Map
In ClementCalenge/adehabitat: Analysis of Habitat Selection by Animals

Description Usage Arguments Value Author(s) See Also Examples

count.points counts the number of points in each pixel of a raster map of class kasc or asc.
count.points.id counts the number of points in each pixel of a raster map of class kasc or asc, for different sets of points (e.g. the relocations of several animals monitored using radio-tracking)

1 2	count.points(xy, w) count.points.id(xy, id, w)

`xy`	a data frame with 2 columns containing the x and y coordinates of the points.
`id`	a factor giving, for each point, the membership of a point to a set.
`w`	an object of class `asc`, `kasc` or `mapattr`.

count.points returns an object of class asc containing the number of points in each cell of the raster map.
count.points.id returns an object of class kasc, with one column per level of the factor id, containing the number of points numbered in each cell of the raster map.

Clement Calenge clement.calenge@oncfs.gouv.fr

kasc for additionnal information on objects of class kasc, and storemapattr for further information on objects of class mapattr.

data(puechabon)
kasc <- puechabon$kasc
locs <-  puechabon$locs

## Counts the number of relocations of each wild boar
## per pixel of the raster map
(nlocrast <- count.points.id(locs[,4:5], locs[,1], kasc))
image(nlocrast)

## Counts the number of all relocations
## per pixel of the raster map
(nlocrast <- count.points(locs[,c("X","Y")], kasc))
image(nlocrast)