marktable
Tabulate Marks in Neighbourhood of Every Point in a Point Pattern
Visit each point in a point pattern, find the neighbouring points, and compile a frequency table of the marks of these neighbour points.
- Keywords
- spatial, programming
Usage
marktable(X, R, exclude=TRUE)
Arguments
- X
- A marked point pattern.
An object of class
"ppp"
. - R
- Neighbourhood radius.
- exclude
- Logical. If
exclude=TRUE
, the neighbours of a point do not include the point itself. Ifexclude=FALSE
, a point belongs to its own neighbourhood.
Details
This algorithm visits each point in the point pattern X
,
inspects all the neighbouring points within a radius R
of the current
point, and compiles a frequency table of the marks attached to the
neighbours.
The dataset X
must be a multitype point pattern, that is,
marks(X)
must be a factor
.
The result is a two-dimensional contingency table with one row for
each point in the pattern, and one column for each possible mark
value. The [i,j]
entry in the table gives the number of
neighbours of point i
that have mark j
.
To perform more complicated calculations on the neighbours of every
point, use markstat
or applynbd
.
Value
- A contingency table (object of class
"table"
) with one row for each point inX
, and one column for each possible mark value.
See Also
Examples
data(amacrine)
head(marktable(amacrine, 0.1))
head(marktable(amacrine, 0.1, exclude=FALSE))