.BG
.FN symbols
.TL
Draw Symbols on a Plot
.CS
symbols(x, y, circles=, squares=, rectangles=,
        stars=, thermometers=, boxplots=,
        add=FALSE, inches=TRUE)
.XY
.AG circles=
radii of circles.
.AG squares=
lengths of the sides of squares.
.AG rectangles=
matrix whose two columns give widths and heights of
rectangles.
.AG stars=
matrix with `n' columns, where `n' is the number of points
to a star.  The matrix should be scaled from 0 to 1.
.AG thermometers=
matrix with 3 or 4 columns.
The first two columns give the widths and heights of rectangular
thermometer symbols.
If the matrix has 3 columns, the third column gives the fraction of
the symbol that is filled (from bottom up).
If the matrix has 4 columns, the third and fourth columns give the fractions
of the rectangle between which is filled.
.AG boxplots=
matrix with 5 columns, giving the width and height of the box,
the amount to extend on the top and bottom, and the fraction
of the way up the box to draw the median line.
.AG add
logical flag. If `FALSE', a new plot is set up.  If `TRUE',
symbols are added to the existing plot.
.AG inches
if `FALSE', the symbol parameters are interpreted as being in
units of `x' and `y'.  If `TRUE', the symbols are
scaled so that the largest symbol is one inch in size.  If a
number is given, the parameters are scaled so that `inches'
is the size of the largest symbol in inches.
.PP
Only one of the arguments `circles', `squares', `rectangles',
`stars', `thermometers', or `boxplots' can be given.
.GR
.Tl
.EX
symbols(x,y,circle=radii,inches=5)
      #  largest circle has radius  5 inches

p <- apply(parm,2,range)  #find min/max of each column of parm
pscale <- scale(p,center=p[1,],scale=p[2,]-p[1,])
symbols(x,y,stars=pscale) # plot stars
.KW aplot
.KW hplot
.WR
