* see comments at end-of-file

program define gr3
version 2.1
	if substr("%_1",1,1)=="," | "%_1"=="" { 
		_3drshow %_*
		exit
	}
	capture conf var _vy _vyy _vx
	if _rc==0 { 
		#delimit ;
		di in red "3d graph data in memory; use " in wh "restore"
		in red " first or do not specify varlist" ; 
		#delimit cr ; 
		exit 198
	}
	_3ddflts
	mac def _varlist "req ex min(3) max(3)"
	mac def _if "opt"
	mac def _in "opt"
	mac def _options "Rot(int %D3rot) Elev(int %D3elev) Symbol(string) *"
	parse "%_*"

	if "%_symbol"=="" { mac def _symbol "o" }
	else if substr("%_symbol",1,1)=="[" & substr("%_symbol",-1,1)=="]" { 
		parse "%_symbol", parse("[] ")
		confirm var %_2
		mac def _keep "%_2"
	}

	parse "%_varlist", parse(" ")
	_3dsvusr
	capture { 			/* begin break-key capture	*/
		if "%_if`%_in"!="" { keep %_if %_in } 
		_3dmkdta %_1 %_2 %_3 %_keep
		_3drproj %_rot %_elev
		mac def D3vnames "%_1 %_2 %_3"
		if "%D3shad"=="on" { _3dshad }
		_3drshow, sym(%_symbol) %_options
		#delimit ; 
		di in gr _n 
		"  note:  The converted data has been left in memory." _n  
		"         Type '" in wh "restore" in gr  
				"'to obtain your original data." _n 
		"         Use  '" in wh "gr3" in gr "' to redisplay graph." ;
		#delimit cr
		exit
	}
	mac def _rc = _rc 		/* error-abort			*/
	restore
	exit %_rc
end
exit

/*
	gr3:  general routine for 3d scatter

		gr3 [xvar yvar zvar] [, options]

	If varlist not specified, taken as request to redisplay last graph.
	This is handled by calling _3drshow.

	Otherwise, request to handle this graph.

	See _3drshow for list of options.
*/


/*
        3d graphic routines
        	Copyright (c) 1991 by C.R.C.
		1640 Fifth Street
		Santa Monica, California 90401
        	1-800-STATAPC  

*/



/*
	Command Summary:
 
	Top Level:
		gr3             make a 3-d scatterplot
		restore         retrieve user data (see explanation below)
		gr3save		save 3d data
		gr3use		use 3d data
		gr3set		set defaults
		gr3q		query defaults

	Middle Level:
		_3dproj         make a projection
		_3drshow	reshow last 3d scatterplot

	Low Level:
		_3ddflts	set defaults to default values
		_3dmkdta	make dtaset containing scaled _x _y _z; add axis
		_3drproj	reproject at specified angles

		_3dax0		add axis through (0,0,0) to data
		_3daxmin	add axis through (min,min,min) to data
		_3daxout	add "outline" axis to data
		_3daxtbl	add "table" axis to data
		
		_3dmnmx		rescale variable to range [0,1]
		_3ddflts	set default values in macros
		_3dsvusr	save user data set (also see restore)

	Global macros used:
		D3vnames	names of variables graphed

		D3rot		default value of rotation
		D3elev		default value of elevation
		D3tilt		default value of tilt (always 0)
		D3shad		on or off (default off)

		D3lrot		rotation of current graph
		D3lelev		elevation of current graph
		D3ltilt		tilt of current graph (always 0)

		D3_LFN		Last S_FN (for re-using data)

	Notes:

		These routines create working data sets, all named _XXX.dta.
		These should no be removed while you are using the gr3 
		routines.  You may erase the data sets freely between times, 
		since this file recreates necessary data sets.

	Description of 3d data set:

		_x _y _z	contain rescaled (min=0, max=1) variables
				to be graphed

		_Type		. if original data
				2 if axis information
				3 if shadow information

		_vy _vx		Projection of _x _y _z 
		_vyy		Projection of axis (_vyy _vx)
		_vyl		Projection of labeling (_vyl, _vx)
		_name		names to be printed at (_vyl, _vx)
		_vybase		Projection of (_x,_y,0)  (_vybase _vx)
		_shadow		only if shadow information,
				projection of (_x,0,_z) (_shadow _vx)
*/