extract.data {SDMTools} | R Documentation |
extract.data
extracts data from raster object of class 'asc' at
specified locations. This represents a faster version of 'join.asc' of the
adehabitat package that assumes all locations are within the map extents.
Note: there is no interpolation done here. The values reported are simply the values of the raster cell the point falls into.
extract.data(pts,x)
pts |
a two-column data frame with the x and y coordinates of the locations of interest. |
x |
an object of class "asc" as defined in the adehabitat package |
Implements a faster version of 'join.asc' from the adehabitat package. NOTE: this assumes all locations are within the extent of the raster map.
Returns a vector equal in length to the number of locations in pnts.
Jeremy VanDerWal jjvanderwal@gmail.com
#create a simple object of class 'asc' tasc = as.asc(matrix(1:50,nr=50,nc=50)); print(tasc) #define some point locations points = data.frame(x=runif(25,1,50),y=runif(25,1,50)) #extract the data points$values = extract.data(points,tasc) #show the data print(points)