Coverage for local/lib/python2.7/site-packages/sage/geometry/polyhedron/cdd_file_format.py : 97%

""" 

Generate cdd ``.ext`` / ``.ine`` file format 

""" 

######################################################################## 

# Copyright (C) 2008 Marshall Hampton <hamptonio@gmail.com> 

# Copyright (C) 2011 Volker Braun <vbraun.name@gmail.com> 

# 

# Distributed under the terms of the GNU General Public License (GPL) 

# 

# http://www.gnu.org/licenses/ 

######################################################################## 

from __future__ import print_function 

from __future__ import absolute_import 

from .misc import _set_to_None_if_empty, _common_length_of, _to_space_separated_string 

######################################################################### 

def cdd_Vrepresentation(cdd_type, vertices, rays, lines, file_output=None): 

r""" 

Return a string containing the V-representation in cddlib's ext format. 

INPUT: 

- ``file_output`` (string; optional) -- a filename to which the 

representation should be written. If set to ``None`` (default), 

representation is returned as a string. 

.. NOTE:: 

If there is no vertex given, then the origin will be implicitly 

added. You cannot write the empty V-representation (which cdd would 

refuse to process). 

EXAMPLES:: 

sage: from sage.geometry.polyhedron.cdd_file_format import cdd_Vrepresentation 

sage: print(cdd_Vrepresentation('rational', [[0,0]], [[1,0]], [[0,1]])) 

V-representation 

linearity 1 1 

begin 

3 3 rational 

0 0 1 

0 1 0 

1 0 0 

end 

TESTS:: 

sage: from sage.misc.temporary_file import tmp_filename 

sage: filename = tmp_filename(ext='.ext') 

sage: cdd_Vrepresentation('rational', [[0,0]], [[1,0]], [[0,1]], file_output=filename) 

""" 

vertices = _set_to_None_if_empty(vertices) 

rays = _set_to_None_if_empty(rays) 

lines = _set_to_None_if_empty(lines) 

num, ambient_dim = _common_length_of(vertices, rays, lines) 

# cdd implicitly assumes that the origin is a vertex if none is given 

if vertices is None: 

vertices = [[0]*ambient_dim] 

num += 1 

s = 'V-representation\n' 

if lines is not None: 

n = len(lines) 

s += "linearity " + repr(n) + ' ' 

s += _to_space_separated_string(range(1,n+1)) + '\n' 

s += 'begin\n' 

s += ' ' + repr(num) + ' ' + repr(ambient_dim+1) + ' ' + cdd_type + '\n' 

if lines is not None: 

for l in lines: 

s += ' 0 ' + _to_space_separated_string(l) + '\n' 

if rays is not None: 

for r in rays: 

s += ' 0 ' + _to_space_separated_string(r) + '\n' 

if vertices is not None: 

for v in vertices: 

s += ' 1 ' + _to_space_separated_string(v) + '\n' 

s += 'end\n' 

if file_output is not None: 

in_file = open(file_output, 'w') 

in_file.write(s) 

in_file.close() 

else: 

return s 

######################################################################### 

def cdd_Hrepresentation(cdd_type, ieqs, eqns, file_output=None): 

r""" 

Return a string containing the H-representation in cddlib's ine format. 

INPUT: 

- ``file_output`` (string; optional) -- a filename to which the 

representation should be written. If set to ``None`` (default), 

representation is returned as a string. 

EXAMPLES:: 

sage: from sage.geometry.polyhedron.cdd_file_format import cdd_Hrepresentation 

sage: cdd_Hrepresentation('rational', None, [[0,1]]) 

'H-representation\nlinearity 1 1\nbegin\n 1 2 rational\n 0 1\nend\n' 

TESTS:: 

sage: from sage.misc.temporary_file import tmp_filename 

sage: filename = tmp_filename(ext='.ine') 

sage: cdd_Hrepresentation('rational', None, [[0,1]], file_output=filename) 

""" 

ieqs = _set_to_None_if_empty(ieqs) 

eqns = _set_to_None_if_empty(eqns) 

num, ambient_dim = _common_length_of(ieqs, eqns) 

ambient_dim -= 1 

s = 'H-representation\n' 

if eqns is not None: 

assert len(eqns)>0 

n = len(eqns) 

s += "linearity " + repr(n) + ' ' 

s += _to_space_separated_string(range(1,n+1)) + '\n' 

s += 'begin\n' 

s += ' ' + repr(num) + ' ' + repr(ambient_dim+1) + ' ' + cdd_type + '\n' 

if eqns is not None: 

for e in eqns: 

s += ' ' + _to_space_separated_string(e) + '\n' 

if ieqs is not None: 

for i in ieqs: 

s += ' ' + _to_space_separated_string(i) + '\n' 

s += 'end\n' 

if file_output is not None: 

in_file = open(file_output, 'w') 

in_file.write(s) 

in_file.close() 

else: 

return s