Coverage for local/lib/python2.7/site-packages/sage/graphs/dot2tex_utils.py : 25%

r""" 

This file contains some utility functions for the interface with dot2tex 

""" 

#***************************************************************************** 

# Copyright (C) 2010 Nicolas M. Thiery <nicolas.thiery at u-psud.fr> 

# 

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

# http://www.gnu.org/licenses/ 

#***************************************************************************** 

from __future__ import print_function 

import re 

from sage.misc.latex import latex 

from sage.misc.cachefunc import cached_function 

@cached_function 

def have_dot2tex(): 

""" 

Returns whether ``dot2tex`` >= 2.8.7 and graphviz are installed 

and functional 

EXAMPLES:: 

sage: sage.graphs.dot2tex_utils.have_dot2tex() # optional - dot2tex graphviz 

True 

sage: sage.graphs.dot2tex_utils.have_dot2tex() in [True, False] 

True 

""" 

try: 

import dot2tex 

# Test for this required feature from dot2tex 2.8.7 

return dot2tex.dot2tex("graph {}", format = "positions") == {} 

except (Exception, SystemExit): 

return False 

def assert_have_dot2tex(): 

""" 

Tests whether ``dot2tex`` >= 2.8.7 and graphviz are installed and 

functional, and raises an error otherwise 

EXAMPLES:: 

sage: sage.graphs.dot2tex_utils.assert_have_dot2tex() # optional - dot2tex graphviz 

""" 

check_error_string = """ 

An error occurs while testing the dot2tex installation. 

Please see :meth:`sage.graphs.generic_graph.GenericGraph.layout_graphviz` 

and check the installation of graphviz and the dot2tex spkg. 

For support, please contact <sage-combinat-devel at googlegroups.com>. 

""" 

import_error_string = """ 

An error occured when importing dot2tex. 

Please see :meth:`sage.graphs.generic_graph.GenericGraph.layout_graphviz` 

for installation instructions. 

""" 

try: 

import dot2tex 

except ImportError as e: 

print(import_error_string) 

raise # re-raise current exception 

else: 

if dot2tex.dot2tex("graph {}", format = "positions") != {}: 

raise RuntimeError(check_error_string) 

def quoted_latex(x): 

""" 

Strips the latex representation of ``x`` to make it suitable for a 

``dot2tex`` string. 

EXAMPLES:: 

sage: sage.graphs.dot2tex_utils.quoted_latex(matrix([[1,1],[0,1],[0,0]])) 

'\\left(\\begin{array}{rr}1 & 1 \\\\0 & 1 \\\\0 & 0\\end{array}\\right)' 

""" 

return re.sub("\"|\r|(%[^\n]*)?\n","", latex(x)) 

def quoted_str(x): 

""" 

Strips the string representation of ``x`` to make it suitable for 

a ``dot2tex`` string, and especially a node label (``dot2tex`` 

gets confused by newlines, and braces) 

EXAMPLES:: 

sage: sage.graphs.dot2tex_utils.quoted_str(matrix([[1,1],[0,1],[0,0]])) 

'[1 1]\\n\\\n[0 1]\\n\\\n[0 0]' 

sage: print(sage.graphs.dot2tex_utils.quoted_str(matrix([[1,1],[0,1],[0,0]]))) 

[1 1]\n\ 

[0 1]\n\ 

[0 0] 

""" 

return re.sub("\n",r"\\n\\"+"\n", re.sub("\"|\r|}|{","", str(x)))