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Copyright © 1995, 1997 The Geometry Center, Minneapolis MN
Synopsis Main Output Formats Geomview Print Qhull Precision Trace
Use options 'Po' and 'Q0' if you can not merge facets. Option 'Po' can not force output when duplicate ridges or duplicate facets occur. It may produce erroneous results. For these reasons, merged facets or exact arithmetic may be better.
If you need a simplicial Delaunay triangulation, use option 'Ft'. If you need a simplicial triangulation of the original input sites, use 'Q0' . If 'Q0' reports precision problems, use exact arithmetic or 'Po'.
Option 'Po' may be used without 'Q0' to remove some steps from Qhull or to output the neighborhood of an error.
If option 'Po' is used,
If an error occurs before the completion of Qhull and tracing is not active, 'Po' outputs a neighborhood of the erroneous facets (if any). It uses the current output options.
With option 'Pp', Qhull does not print statistics about precision problems, and it removes some of the warnings.
Qhull can mark facets as "good". This is used to
Option 'Pg' only prints good facets that also meet 'Pdk' and 'PDk' options. It is automatically set for options 'PAn' and 'PFn '.
Option 'PG' can be used with or without option 'Pg' to print the neighbors of good facets. For example, options 'QGn ' and 'QVn' print the horizon facets for point n.
For example, 'Pd0:0.5' does not print facets with normal[0] <= 0.5 . The default value of n is zero. For example in 3-d, 'Pd0d1d2' displays facets in the positive octant. If no facets match, the closest facet is returned.
For example, 'PD0:0.5' does not print facets with normal[0] >= 0.5 . The default value of n is zero. For example in 3-d, 'PD0D1D2' displays facets in the negative octant. If no facets match, the closest facet is returned.
In 2-d, 'd G PD2' displays the Delaunay triangulation instead of the corresponding paraboloid.
Be careful of placing 'Dk' or 'dk' immediately after a real number. Some compilers treat the 'D' as a double precision exponent.
The n largest facets are marked good for printing. This may be useful for approximating a hull. Unless 'PG' is set, 'Pg' is automatically set.
The facets with area at least n are marked good for printing. This may be useful for approximating a hull. Unless 'PG' is set, 'Pg' is automatically set.
The n facets with the most merges are marked good for printing. This may be useful for approximating a hull. Unless 'PG' is set, 'Pg' is automatically set.
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Comments to: qhull@geom.umn.edu
Created: Sept. 25, 1995 --- Last modified: see top