R/orglcenter.R

In zdealveindy/ordijuice: Unconstrained ordinations of vegetation data in JUICE program

orglcenter <-
function (object, groups, display = "sites", w = weights(object, 
    display), choices = 1:3, ...) 
{
    weights.default <- function(object, ...) NULL
    pts <- scores(object, display = display, choices = choices, ...)
    out <- seq(along = groups)
    w <- eval(w)
    if (length(w) == 1) w <- rep(1, nrow(pts))
    if (is.null(w)) w <- rep(1, nrow(pts))
    inds <- names(table(groups))
    shift <- 0.02 * diff (range (pts[,1]))
    for (is in inds) {
      gr <- out[groups == is]
      if (length(gr) > 1)
        {
        X <- pts[gr, ]
        W <- w[gr]
        ave <- apply(X, 2, weighted.mean, w = W)
        rgl.texts(ave[1]+shift, ave[2]+shift, ave[3]+shift, text = is, col = 'black', ...)
        }
      if (length (gr) == 1)
        {
        X <- pts[gr, ]
        rgl.texts (X+shift, text = is, col = 'black', ...)
        }
      }
  invisible()
}