bw.pplHeat {spatstat.explore} | R Documentation |
Bandwidth Selection for Diffusion Smoother by Likelihood Cross-Validation
Description
Selects an optimal bandwidth for diffusion smoothing by point process likelihood cross-validation.
Usage
bw.pplHeat(X, ..., srange=NULL, ns=16, sigma=NULL,
leaveoneout=TRUE, verbose = TRUE)
Arguments
X |
Point pattern (object of class |
... |
Arguments passed to |
srange |
Numeric vector of length 2 specifying a range of bandwidths to be considered. |
ns |
Integer. Number of candidate bandwidths to be considered. |
sigma |
Maximum smoothing bandwidth.
A numeric value, or a pixel image, or a |
leaveoneout |
Logical value specifying whether intensity values at data points should be estimated using the leave-one-out rule. |
verbose |
Logical value specifying whether to print progress reports. |
Details
This algorithm selects the optimal global bandwidth for
kernel estimation of intensity for the dataset X
using diffusion smoothing densityHeat.ppp
.
If sigma
is a numeric value, the algorithm finds the
optimal bandwidth tau <= sigma
.
If sigma
is a pixel image or function, the algorithm
finds the optimal fraction 0 < f <= 1
such that
smoothing with f * sigma
would be optimal.
Value
A numerical value giving the selected bandwidth
(if sigma
was a numeric value)
or the selected fraction of the maximum bandwidth
(if sigma
was a pixel image or function).
The result also belongs to the class "bw.optim"
which can be
plotted.
Author(s)
Adrian Baddeley and Tilman Davies.
See Also
bw.CvLHeat
for an alternative method.
Examples
online <- interactive()
if(!online) op <- spatstat.options(npixel=32)
f <- function(x,y) { dnorm(x, 2.3, 0.1) * dnorm(y, 2.0, 0.2) }
X <- rpoint(15, f, win=letterR)
plot(X)
b <- bw.pplHeat(X, sigma=0.25)
b
plot(b)
if(!online) spatstat.options(op)