| areaGain {spatstat} | R Documentation |
Computes the area of that part of a disc that is not covered by other discs.
areaGain(u, X, r, W=NULL, ngrid=spatstat.options("ngrid.disc"))
u |
Coordinates of the centre of the disc of interest.
A vector of length 2.
Alternatively, a point pattern (object of class "ppp").
|
X |
Locations of the centres of other discs.
A point pattern (object of class "ppp").
|
r |
Disc radius, or vector of disc radii. |
W |
Optional. Window (object of class "owin")
in which the area should be computed.
|
ngrid |
Dimensions of the ngrid * ngrid array of test points
that will be used to estimate the uncovered area.
|
This function computes the area of that part of
the disc of radius r centred at the location u
that is not covered by any of the discs of radius r
centred at the points of the pattern X.
This area is important in some calculations related to
the area-interaction model AreaInter.
If u is a point pattern and r is a vector,
the result is a matrix, with one row for each point in u
and one column for each entry of r. The [i,j] entry
in the matrix is the area of that part of the disc of radius
r[j] centred at the location u[i] that is
not covered by any of the discs of radius r[j]
centred at the points of the pattern X.
If W is not NULL, then the areas are computed only
inside the window W. Currently this is implemented only for
rectangular windows.
The area is calculated by discrete approximation, using an
ngrid * ngrid grid of test points.
A matrix with one row for each point in u
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) u <- c(0.5,0.5) areaGain(u, cells, 0.1)