adehabitatMA (version 0.3.17)

count.points: Number of Points in Each Pixel of a Raster Map

Description

count.points counts the number of points in each pixel of a raster map inheriting the class SpatialPixels.

Usage

count.points(xy, w)

Value

an object of class SpatialPixelsDataFrame containing the number of points in each cell of the raster map. If xy is a

SpatialPointsDataFrame with one column (a factor), the resulting object contains one column per level of this factor.

Arguments

xy

an object of class SpatialPoints, or SpatialPointsDataFrame with one column. In the latter case, the column is considered as a factor giving, for each point, the membership of the point to a set.

w

an object inheriting the class SpatialPixels.

Author

Clement Calenge

See Also

SpatialPixelsDataFrame-class for additionnal information on objects of class SpatialPixelsDataFrame.

Examples

data(lynxjura)

# locs is the SpatialPointsDataFrame containing the
# locations of presence indices of Lynx in the Jura mountains (France)
locs <- lynxjura$locs
head(locs)

# sa is the SpatialPixelsDataFrame object containing
# maps of the study area
sa <- lynxjura$map

# Count all points
cp <- count.points(locs, sa)
cp
image(cp)

# count the points per type of lynx presence indices:
cp <- count.points(locs[,2], sa)
cp