rlabel {spatstat} | R Documentation |
Randomly allocates marks to a point pattern, or permutes the existing marks, or resamples from the existing marks.
rlabel(X, labels=marks(X), permute=TRUE)
X |
Point pattern (object of class "ppp" ).
|
labels |
Vector of values from which the new marks will be drawn at random. Defaults to the vector of existing marks. |
permute |
Logical value indicating whether to generate new marks
by randomly permuting labels or
by drawing a random sample with replacement.
|
This very simple function allocates random marks to
an existing point pattern X
. It is useful
for hypothesis testing purposes.
In the simplest case, the command rlabel(X)
yields
a point pattern obtained from X
by randomly permuting
the marks of the points.
If permute=TRUE
, then labels
should be a vector of
length equal to the number of points in X
.
The result of rlabel
will be a point pattern
with locations given by X
and marks given by
a random permutation of labels
(i.e. a random sample without
replacement).
If permute=FALSE
, then labels
may be a vector of
any length.
The result of rlabel
will be a point pattern
with locations given by X
and marks given by
a random sample from labels
(with replacement).
A marked point pattern.
Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner rolf@math.unb.ca http://www.math.unb.ca/~rolf
setmarks
to assign arbitrary marks.
data(amacrine) # Randomly permute the marks "on" and "off" # Result always has 142 "off" and 152 "on" Y <- rlabel(amacrine) # randomly allocate marks "on" and "off" # with probabilities p(off) = 0.48, p(on) = 0.52 Y <- rlabel(amacrine, permute=FALSE) # randomly allocate marks "A" and "B" with equal probability data(cells) Y <- rlabel(cells, labels=factor(c("A", "B")), permute=FALSE)