Porta was written at theUniversity of Heidelberg to analyze polytopes and
Convex objects are represented in one of two ways:
- ieq files
- namely, lists of inequalities and equalities.
- poi files
- namely, lists of points whose convex hull and convex cone describe
The most basic usage of the program is conversion between these two formats.
Use of the verbose option -v also reports the face-vertex incidence structure.
Porta is installed on the mathlab linux machines utah and tahoe,
in the directory /local/porta.1.3.1. It is also installed on math.cornell.edu in the directory /usr/local_sol/porta. (The subdirectory
man1 has man pages.)
For example, if one wishes to work with the cube of side 2 in 4 dimensions:
- traf -v cube4.ieq
- produces the file cube4.ieq.poi
- traf -v cube4.poi
- produces the file cube4.poi.ieq
The release also comes with files example.ieq and example.poi which illustrate other aspects of the format of data files.
Local Man Pages From Porta 1.3.1
- dim - compute the dimension of convex hull and convex cone for a set of given points
- fctp - checks inequalities for facet-inducing property
- fmel - projection of linear system on subspaces
- ieq - format of '.ieq' - files
- iespo - enumeration of equations and inequalities that are valid for a convex cone and a convex hull
- poi - format of '.poi' - files
- poiieq - format of '.poi' - files
- porta - introduction to the program
- portsort - sort inequalities or point systems
- posie - enumeration of points that are valid for a linear system
- traf - transformation of polyhedral representations
- vint - enumeration of integral linear points of a linear system
Last Update: June 24, 1997