# areaLoss

0th

Percentile

##### Difference of Disc Areas

Computes the area of that part of a disc that is not covered by other discs.

Keywords
spatial, math
##### Usage
areaLoss(X, r, ngrid=spatstat.options("ngrid.disc"), subset=NULL)
##### Arguments
X
Locations of the centres of discs. A point pattern (object of class "ppp").
r
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.
##### Details

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.

##### Value

• A matrix with one row for each point in X (or X[subset]) and one column for each value in r.

AreaInter, areaGain
data(cells)
areaLoss(cells, 0.1, 32)