siberKapow {SIBER}

Calculates the boundary of a union of ellipses

Description

Intended to calculate the area of an ellipse as a proportion of a group of ellipses represented by their union, i.e. the total area encompassed by all ellipses superimposed.

Usage

siberKapow(
  dtf,
  isoNames = c("iso1", "iso2"),
  group = "group",
  pEll = stats::pchisq(1, df = 2)
)

Arguments

dtf

a data.frame object comprising bivariate data as a requirement, and possibly other variables too but these are currently ignored.

isoNames

a character vector of length 2 providing the names of the variables containing the x and y data respectively.

group

a character vector of length 1 providing the name of the grouping variable on which to calculate the KAPOW ellipse.

pEll

the probability ellipse to draw for each group. Defaults to the Standard Ellipse with pEll = stats::pchisq(1, df = 2).

Value

an object of class spatstat.geom::owin containing the numerically calculated ellipses and their union along with the raw ellipse boundaries in both raw and spatstat.geom::owin format.