R/overlap.R

In AndrewLJackson/siar: Stable Isotope Analysis in R

overlap <- function (x1,y1,x2,y2,steps=5) {
  
  .Deprecated("maxLikOverlap", package = "SIBER", "All ellipse and convex hull 
              type analyses in siar are out of date and unsupported. You 
              should use the new stand alone package SIBER instead. See also 
              the function bayesianOverlap in package SIBER.")
  
# calculates the area of overlap between the shapes s1 and s2 which each
# have dimension dim(n,2) where each column are the x and y coordinates
# respectively.

E1 <- standard.ellipse(x1,y1,steps=steps)
E2 <- standard.ellipse(x2,y2,steps=steps)

ex1 <- E1$xSEAc[2:length(E1$xSEAc)]
ey1 <- E1$ySEAc[2:length(E1$xSEAc)]
ex2 <- E2$xSEAc[2:length(E2$xSEAc)]
ey2 <- E2$ySEAc[2:length(E2$xSEAc)]

e1 <- list(x=ex1,y=ey1)
e2 <- list(x=ex2,y=ey2)

out <- list()
out$overlap <- abs(overlap.xypolygon(e1,e2))
out$area1 <- abs(E1$SEAc)
out$area2 <- abs(E2$SEAc)

return(out)

}