areaLoss {spatstat} | R Documentation |
Computes the area of that part of a disc that is not covered by other discs.
areaLoss(X, r, ngrid=spatstat.options("ngrid.disc"), subset=NULL)
X |
Locations of the centres of discs.
A point pattern (object of class "ppp" ).
|
r |
Disc radius, or vector of disc radii. |
ngrid |
Dimensions of the ngrid * ngrid array of test points
that will be used to estimate the uncovered area.
|
subset |
Optional. Index identifying a subset of the points of X
for which the area difference should be computed.
|
This function computes, for each point X[i]
in X
and for each radius r
,
the area of that part of the disc of radius r
centred at the
location X[i]
that is not covered by any of the
other discs of radius r
centred at the points X[j]
for j
not equal to i
.
This area is important in some calculations related to
the area-interaction model AreaInter
.
The result is a matrix, with one row for each point in X
and one column for each entry of r
.
The area is calculated by discrete approximation, using an
ngrid * ngrid
grid of test points.
A matrix with one row for each point in X
(or X[subset]
)
and one column for each value in r
.
Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner r.turner@auckland.ac.nz
data(cells) areaLoss(cells, 0.1, 32)