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help for ^condraw^                             (STB-23: gr16; STB-41: gr16.2)
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Graph convex hulls               
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    ^condraw^ varlist, ^h^ull(#) ^g^roup(str) ^gr^no(#) ^d^r(str) ^v^id(str)


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

Graphs the convex hulls generated by the ^conhull^ ado file.  The program
generates new variables for graphing the hulls and adds new observations
so STATA can connect the points on the hull.  After the graph is displayed
the user can redraw the graph with different options and/or save it.
By dropping the created variables and the new observations the data can be
used to generate new graphs.

The varlist contains the names of the variables containing the x and y
coordinates of points and the name on the variable containing the convex
hull number.

Options allow the user to control the graphs produced.  Three
situations are possible.

  1. ^condraw x y conhull^ assumes that ^conhull^ generated one or more hulls
  for the entire set of points and placed them in variable conhull.  Since
  the option ^hull^ is not specified the outermost convex hull is graphed.
  The command ^condraw y conhull, hu(2)^ graphs the second hull.

  2. ^condraw x y conhull, gr(smoke)^ assumes that ^conhull^ generated one or
  more hulls for each class of a categorical variable, "smoke".  Without the
  ^hull^ option the outermost hull for each class is graphed. The command
  ^condraw x y conhull,g(smoke) h(3)^ graphs the third hull for each class
  of the categorical variable.

  3. ^condraw x y conhull, gr(smoke) gr(2) h(2)^ assumes that ^conhull^
  generated one or more hulls for each class of a categorical variable 
  "smoke", but the user desires to graph only the second outermost hull for
  the second level of "smoke".  

Note that using ^condraw x y conhull^ on a data set for which  ^conhull^
generated hulls for each class of a categorical variable will produce
a graph in which the points are not connected properly.


Options
-------

^hull(^#^)^ specifies the hull to be graphed.  The default is to graph
   the outermost hull.

^group(^str^)^ is the name of a categorical variable for which convex hulls
   were generated.  The default is to assume the entire sample was used to
   generate the hulls.

^grno(^#^)^ specifies which class of the categorical variable identified
   by ^group(^str^)^ is to be used in the graph.  The default is to use all
   classes.  If more than one, but fewer than all, classes are desired the
   user should use the default option and then eliminate the undesired
   classes when regraphing the data.

^dr(^str^)^ names a marker variable that allows the points in the graph to
   be closed.  The default is "dr".  As this is not a temporary variable
   a ^dr already defined^ error message will appear if you use the default
   and your data set contains a variable named "dr".

^vid(^str^)^ names the new variables needed for graphing the hulls.  The 
   default is "hv*".  ^condraw x y,g(smoke) h(3)^ graphs the third outermost
   hull for the levels of categorical variable "smoke".  If "smoke" has three
   levels three new variables are created: "hv1" "hv2" "hv3".  As these are
   not temporary variables a ^hv1 already defined^ error message will appear
   if you use the default and your data set contains a variable named "hv1".


Authors
-------

        J. Patrick Gray
        Department of Anthropology
        University of Wisconsin-Milwaukee
        Milwaukee, WI 53201
        jpgray@@alpha1.csd.uwm.edu

        Tim McGuire
        Computer Information Systems
        WTAMU, BOX 268
        West Texas A&M University
        Canyon, TX  79016


Also see
--------

    STB:  STB-41 gr16.2, STB-26 gr16
On-line:  help for @conhull@