plot.scan.test
Plot Result of Scan Test
Computes or plots an image showing the likelihood ratio test statistic for the scan test, or the optimal circle radius.
Usage
## S3 method for class 'scan.test':
plot(x, \dots, what=c("statistic", "radius"),
do.window = TRUE) ## S3 method for class 'scan.test':
as.im(X, \dots, what=c("statistic", "radius"))
Arguments
- x,X
- Result of a scan test. An object of class
"scan.test"produced byscan.test. - ...
- Arguments passed to
plot.imto control the appearance of the plot. - what
- Character string indicating whether to produce an image of the
(profile) likelihood ratio test statistic (
what="statistic", the default) or an image of the optimal value of circle radius (what="radius"). - do.window
- Logical value indicating whether to plot the original window of the data as well.
Details
These functions extract, and plot, the spatially-varying value of the likelihood ratio test statistic which forms the basis of the scan test.
If the test result X was based on circles of
the same radius r, then as.im(X) is a pixel image
of the likelihood ratio test statistic as a function of the
position of the centre of the circle.
If the test result X was based on circles of
several different radii r, then as.im(X) is a pixel image
of the profile (maximum value over all radii r)
likelihood ratio test statistic as a function of the
position of the centre of the circle, and
as.im(X, what="radius") is a pixel image giving
for each location $u$ the value of r which maximised
the likelihood ratio test statistic at that location.
The plot method plots the corresponding image.
Value
- The value of
as.im.scan.testis a pixel image (object of class"im"). The value ofplot.scan.testisNULL.
See Also
Examples
if(interactive()) {
a <- scan.test(redwood, seq(0.04, 0.1, by=0.01),
method="poisson", nsim=19)
} else {
a <- scan.test(redwood, c(0.05, 0.1), method="poisson", nsim=2)
}
plot(a)
as.im(a)
plot(a, what="radius")