REDUCE

16.50 QHULL: Compute the complex hull

This package is an interface to qhull (www.qhull.org), which has to be installed externally. There are 3 options for this package to find the qhull program:

  1. Put it into the path of your shell (recommended).
  2. Set and export an environment variable QHULL to the complete path, e.g., in the Bash:
    export QHULL=/usr/bin/qhull

  3. Inside Reduce set the variable qhull_call!* to the complete path, e.g.,
    symbolic(qhull_call!* := "/usr/bin/qhull");

Example: Compute the convex hull of a list integer points as a subset of that list as follows:

1: qhull {{2,0,0}, {0,2,0}, {0,2,2}, {0,0,0}, {1,1,1}};  
 
{{2,0,0},{0,2,0},{0,2,2},{0,0,0}}  
 
2: symbolic;  
 
nil  
 
3* qhull_qhull {{2,0,0}, {0,2,0}, {0,2,2}, {0,0,0}, {1,1,1}};  
 
((2 0 0) (0 2 0) (0 2 2) (0 0 0))

Author: Thomas Sturm, March 2013