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help for ^chplot^                                                (STB-36: gr16.1)
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Convex hull plot
----------------

    ^chplot^ yvar xvar [^if^ exp] [^in^ range]
        [^, h^ull^(^#^)^ ^hv(^hullvar^)^ ^movie^ graph_options]


Description
-----------

^chplot^ is an interface to ^conhull^ and ^condraw^ which produces a
scatter plot of yvar versus xvar with one convex hull superimposed.

^conhull^ and ^condraw^ must be installed separately.


Options
-------

^hull(^#^)^ specifies the convex hull required. The default is 1, the
    outermost hull.

^hv(^hullvar^)^ specifies a variable to hold information about the hulls
    and is only needed if ^_hull1^ is a variable in the data set.

^movie^ specifies that the final graph (for ^hull^ > 1) is to be preceded
    by a movie of the hulls up to ^hull^. Thus ^hull(2) movie^ means
    that the final graph includes hull 2 and that hulls 1 and 2 will be
    shown separately beforehand.

graph_options are any options allowed with ^graph, twoway^. See help on
    @graph@. Defaults are ^c(.l) sy(oi) t1(" ")^ and ^l1^ and ^b1^
    indicating y and x variables as usual.


Example
-------

        . ^chplot length width^
        . ^chplot length width, xlog ylog xla(200,500,1000,2000)^
          ^yla(200,500,1000,2000)^


Author
------
         Nicholas J. Cox
         University of Durham, U.K.
         n.j.cox@@durham.ac.uk


Also see
--------

    STB:  STB-36 gr16.1, STB-23 gr16
 Manual:  [R] graph
On-line:  help for @conhull@ (if installed), @condraw@ (if installed), @graph@