plmark {plgraphics}

Labels for Extreme Points

Description

Determine extreme points and get labels for them.

Usage

plmark(x, y = NULL, markextremes = NULL, plabel = NULL, plargs = NULL, ploptions = NULL)

Arguments

x, y

coordinates of points. If x is of length 0, it is retrieved from plargs$pldata[,1].

markextremes

proportion of extreme points to be 'marked'. This may be a list of proportions with names indicating the variables for which the proportion is to be applied. If a vector (of length 2), the elements define the proportions for the lower and upper end, respectively. In the default case (NULL), the proportion is obtained from ploptions, which in turn leads to calling the function markextremes with the argument equal to the number of (finite) observations.

plabel

character vector of labels to be used for extreme points. If NULL, they are obtained from plargs$plabel.

plargs, ploptions

result of pl.control, cf plpoints

Value

A character vector in which the 'marked' observations contain the respective label and the others equal "".

Author(s)

Werner A. Stahel

See Also

plyx

Examples

  plyx(Sepal.Width ~ Sepal.Length, data=iris)
  ( t.plab <-
    plmark(iris$Sepal.Length, iris$Sepal.Width, markextremes=0.03) )