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piechart()

Usage:
piechart(p [,start:p0] [,labels:labs] [,rlab:r1 [, rval:r2]\
  [, xwidth:w] [,graphics keyword phrases]), REAL vector p with p[i] >=
  0, p0 >= 0, REAL scalar, CHARACTER vector labs, REAL scalars r1 > 0,
  r2 > 0, w > 0



Keywords: distribution graphs
                                  Usage
piechart(p) draws a pie chart of data in REAL vector p which should
have no MISSING values and satisfy min(p) >= 0.  The chart is drawn in
a circle with radius 1.

Usually p is a vector of proportions (sum(p) = 1) or percentages
(sum(p) = 100), but this is not required.  What is actually drawn is a
pie chart with sector angles computed from the proportions p1 =
p/sum(p).  The angle defining sector I of the pie chart, going
clockwise around the circle is 360*p1[I] degrees.  By default, the
starting edge of sector 1 is vertical.  Each sector is is labelled by
sector number, from 1 to nrows(p).

There several optional keywords.

                            Optional Keywords
start
  piechart(p, start:p0 [,other keywords]) where p0 is a REAL scalar
  draws a pie chart with the starting sector edge located p0 of a cycle
  (abs(p0) <= 1) or p0 percent of a cycle (abs(p0) > 1) around the
  circle from the vertical.  For instance, with p0 = .25 or 25, the
  starting sector edge is 90 degrees clockwise from the vertical.
  'start' can be used with other keywords.

labels
  piechart(p, labels:labs [,other keywords]), where labs is a CHARACTER
  vector with length(labs) = length(p), labels sector I with labs[I].
  You can suppress sector labelling with labels:"".

rlab
  piechart(p, rlab:r1 [,labels:labs] [,other keywords]) puts sector
  labels at radius r1 > 0 from the pie center.  Usually r1 < 1.  The
  default radius is .9.

rval
  piechart(p, rval:r2 [,other keywords]), prints p[I] at radius r2 > 0
  in sector I, I = 1, ..., length(p).  Usually r2 < 1.  This allows you
  to label sectors both with a descriptive tag and the value of the
  data.

xwidth
  piechart(p, xwidth:w [other keywords]) includes 'xmin:-w/2,xmax:w/2'
  in the argument list of the plotting commands that draw the pie
  chart.  You need to use 'xwidth' only when the plot without it looks
  like an ellipse instead of a circle.  The default is 'xwidth:3.2'.

You can also use many of the usual graphics keywords like 'xlab',
'ylab', 'title' and 'window'.  See topic 'graph_keys'.

                              Adding labels
If you don't like the default labeling, you may be able to use Mouse()
and addstrings() to position labels more to your liking.  See Mouse()
and addstrings().


Gary Oehlert 2006-01-30