densityfun.ppp {spatstat} | R Documentation |
Compute a kernel estimate of intensity for a point pattern, and return the result as a function of spatial location.
densityfun(X, ...) ## S3 method for class 'ppp' densityfun(X, sigma = NULL, ..., weights = NULL, edge = TRUE, diggle = FALSE)
X |
Point pattern (object of class |
sigma |
Smoothing bandwidth, or bandwidth selection function,
passed to |
... |
Additional arguments passed to |
weights |
Optional vector of weights associated with the points of |
edge,diggle |
Logical arguments controlling the edge correction.
Arguments passed to |
The commands densityfun
and density
both perform kernel estimation of the intensity of a point pattern.
The difference is that density
returns a pixel image,
containing the estimated intensity values at a grid of locations, while
densityfun
returns a function(x,y)
which can be used
to compute the intensity estimate at any spatial location.
For purposes such as model-fitting it is more accurate to
use densityfun
.
A function
with arguments x,y
returning values of the intensity.
The function also belongs to the class "densityfun"
which has
methods for print
and as.im
.
It also belongs to the class "funxy"
which has methods
for plot
, contour
and persp
.
Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk.
To interpolate values observed at the points, use Smoothfun
.
f <- densityfun(swedishpines) f f(42, 60) plot(f)