| buffer {adehabitat} | R Documentation |
buffer compute buffers around a set of
locations.
buffer.ani is to be used when the
points can be grouped into several categories (e.g. the relocations
of several animals monitored using radio-tracking; the function
buffer is then applied to each animal).
buffer.line compute buffers around a line.
buffer(pts, x, dist) buffer.ani(pts, fac, x, dist) buffer.line(xy, x, dist)
pts |
a data frame with two columns (x and y coordinates of the points) |
x |
either an object of class asc or kasc with the same
attributes as those desired for the output, or an object of class
mapattr (see storemapattr) |
dist |
a value of distance |
fac |
a factor defining the categories of the points |
xy |
a data frame containing the coordinates of the vertices of the lines |
buffer and buffer.line return an object of class
asc, with 1 for pixels
located within a specified distance of given points, and NA
otherwise.
buffer.ani returns a data frame of class kasc,
with each column corresponding to one level of the factor fac.
Clément Calenge calenge@biomserv.univ-lyon1.fr
as.kasc for additionnal information on
objects of class kasc, import.asc for further
information on objects of class asc, storemapattr
for further information on objects of class mapattr.
data(puechabon)
# locs is the data frame containing the
# relocations of wild boars monitored by radio-tracking
locs <- puechabon$locs
# sa is the "kasc" object of maps of the study area
sa <- puechabon$kasc
# Buffer of 500 m around all relocations
bu <- buffer(locs[,4:5], sa, 500)
image(bu)
# displays all the pixels of the study area within 500 m
# of a relocation of each monitored wild boar
buani <- buffer.ani(locs[,4:5], locs[,1], sa, 500)
image(buani)
## buffer around a trajectory
data(puechcirc)
uu <- puechcirc[burst = "CH930824"]
w <- ascgen(uu[[1]][,c("x","y")], nrcol = 100)
out <- buffer.line(uu[[1]][,c("x","y")], w, 100)
image(out)
plot(uu, asc = out)