R/earth.dist.R

In fossil: Palaeoecological and Palaeogeographical Analysis Tools

`earth.dist` <-
function(lats, dist = TRUE) {
  #tests if lats are a matrix or spatial points
  if (inherits(lats, 'SpatialPoints')) lats<-coordinates(lats)
  name <- list(rownames(lats),rownames(lats))
  n <- nrow(lats)
  z <- matrix(0,n,n,dimnames=name)
  z <- outer(1:n, 1:n, function(i, j) deg.dist(long1 = lats[i, 1], lat1 = lats[i, 2], long2 = lats[j, 1], lat2 = lats[j, 2]))
  #if dist==true then a distance matrix (lower triangle) is returned
  if (dist==TRUE) z<-as.dist(z)
  return(z)
}