

   PPiiee CChhaarrttss

        piechart(x, labels=names(x), shadow=FALSE,
                edges=200, radius=0.8, fill=NULL, main=NULL, ...)

   AArrgguummeennttss::

          x: a vector of positive quantities.  The values in
             `x' are displayed as the areas of pie slices.

     labels: a vector of character strings giving names for the
             slices.

     shadow: a logical vector indicating whether a shadow
             effect should be attempted for the chart.  This
             only makes sense if the slices are filled with
             colors.

      edges: the circular outline of the pie is approximated by
             a polygon with this many edges.

     radius: the pie is drawn centered in a square box whose
             sides range from -1 to 1.  If the character
             strings labeling the slices are long it may be
             necessary to use a smaller radius.

        col: a vector of colors to be used in filling the
             slices.

       main: an overall title for the plot.

        ...: graphical parameters can be given as arguments to
             `piechart'.

   DDeessccrriippttiioonn::

        Pie charts are a very bad way of displaying informa-
        tion.  The eye is good at judging linear measures and
        bad at judging relative areas.  A bar chart or dot
        chart is a preferable way of displaying this type of
        data.

   SSeeee AAllssoo::

        `dotplot'.

   EExxaammpplleess::

        piechart(rep(1,24), col=rainbow(24), radius=0.9)

        pie.sales <- c(0.12, 0.3, 0.26, 0.16, 0.04, 0.12)
        names(pie.sales) <- c("Blueberry", "Cherry",
            "Apple", "Boston Cream", "Other", "Vanilla Cream")
        piechart(pie.sales,
            col=c("purple", "violetred1", "green3",
            "cornsilk", "cyan", "white"))
        piechart(pie.sales,
            col=gray(seq(0.4,1.0,length=6)))

