# The cdd backend for polyhedral computations¶

class sage.geometry.polyhedron.backend_cdd.Polyhedron_QQ_cdd(parent, Vrep, Hrep, **kwds)

Polyhedra over QQ with cdd

INPUT:

• parent – the parent, an instance of Polyhedra.
• Vrep – a list [vertices, rays, lines] or None.
• Hrep – a list [ieqs, eqns] or None.

EXAMPLES:

sage: from sage.geometry.polyhedron.parent import Polyhedra
sage: parent = Polyhedra(QQ, 2, backend='cdd')
sage: from sage.geometry.polyhedron.backend_cdd import Polyhedron_QQ_cdd
sage: Polyhedron_QQ_cdd(parent, [ [(1,0),(0,1),(0,0)], [], []], None, verbose=False)
A 2-dimensional polyhedron in QQ^2 defined as the convex hull of 3 vertices

class sage.geometry.polyhedron.backend_cdd.Polyhedron_RDF_cdd(parent, Vrep, Hrep, **kwds)

Polyhedra over RDF with cdd

INPUT:

• ambient_dim – integer. The dimension of the ambient space.
• Vrep – a list [vertices, rays, lines] or None.
• Hrep – a list [ieqs, eqns] or None.

EXAMPLES:

sage: from sage.geometry.polyhedron.parent import Polyhedra
sage: parent = Polyhedra(RDF, 2, backend='cdd')
sage: from sage.geometry.polyhedron.backend_cdd import Polyhedron_RDF_cdd
sage: Polyhedron_RDF_cdd(parent, [ [(1,0),(0,1),(0,0)], [], []], None, verbose=False)
A 2-dimensional polyhedron in RDF^2 defined as the convex hull of 3 vertices

class sage.geometry.polyhedron.backend_cdd.Polyhedron_cdd(parent, Vrep, Hrep, **kwds)

Base class for the cdd backend.

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A class to keep information about faces of a polyhedron

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The PPL (Parma Polyhedra Library) backend for polyhedral computations