AIMPAC Utilities                                                    envelope(3)
 
NAME
     envelope - produces 3-D envelopes of CUBE output
 
SYNOPSIS
     envelope qubfile envfile
 
DESCRIPTION
 
        The ENVELOPE program reads in a cube of data (qubfile) 
        output by CUBE and produces an iso-valued envelope of the 
        function, output to envfile.  This is done using interactive 
        queries of the user for plotting information.  The resulting 
        file is these redirected to the output device for plotting.
 
ARGUMENTS
 
     qubfile (for example 'hcoh.qub')
        The qubfile contains a cube of data output by the program
        CUBE.
 
     envfile (for example 'hcoh.rel')
        The output envfile contains the plotter calls to produce
        the envelope.  This output file is redirected to the 
        plotter directly. (for example 'cat hcoh.env > /dev/tty02')
 
INTERACTIVE DIALOG
 
        Once the program has read in the cube of data the following
        questions are asked of the user;
 
        1) EYE POSITION
 
        This requests the position of the eye of the viewer.  This point
        can be considered as placed on an extended cube.  A good 
        starting point is 5*NX, 3.5*NY, 2*NZ.  For example, for a 
        100X100X100 cube,
 
        EYE POSITION  500,350,200
 
        would make a good initial guess.
 
        2) OUTER CONTOUR VALUE
 
        This is the value of the iso-surface.
 
        3) LARGER VALUES INSIDE OR OUTSIDE ENVELOPE
 
        The algorithm assumes that either the larger values are inside
        the iso-surface (repsond with -1) or they are outside the
        surface (respond with 1).  If you get a cube as the result try
        using the other response.
 
EXAMPLES
 
     envelope hcoh hcoh
        This requests a calculation of the isovalued envelope of the 
        function in hcoh.qub.
 
SEE ALSO
     cube(3)
 
Release 1.0                       AIMPAC                            envelope(3)