import os
import sys
try:
from hashlib import md5
except ImportError:
from md5 import md5
from docutils import nodes
from docutils.parsers.rst import directives
import warnings
from matplotlib import rcParams
from matplotlib.mathtext import MathTextParser
rcParams['mathtext.fontset'] = 'cm'
mathtext_parser = MathTextParser("Bitmap")
# Define LaTeX math node:
class latex_math(nodes.General, nodes.Element):
pass
def fontset_choice(arg):
return directives.choice(arg, ['cm', 'stix', 'stixsans'])
options_spec = {'fontset': fontset_choice}
def math_role(role, rawtext, text, lineno, inliner,
options={}, content=[]):
i = rawtext.find('`')
latex = rawtext[i+1:-1]
node = latex_math(rawtext)
node['latex'] = latex
node['fontset'] = options.get('fontset', 'cm')
return [node], []
math_role.options = options_spec
def math_directive(name, arguments, options, content, lineno,
content_offset, block_text, state, state_machine):
latex = ''.join(content)
node = latex_math(block_text)
node['latex'] = latex
node['fontset'] = options.get('fontset', 'cm')
return [node]
# This uses mathtext to render the expression
def latex2png(latex, filename, fontset='cm'):
latex = "$%s$" % latex
orig_fontset = rcParams['mathtext.fontset']
rcParams['mathtext.fontset'] = fontset
if os.path.exists(filename):
depth = mathtext_parser.get_depth(latex, dpi=100)
else:
try:
depth = mathtext_parser.to_png(filename, latex, dpi=100)
except:
warnings.warn("Could not render math expression %s" % latex,
Warning)
depth = 0
rcParams['mathtext.fontset'] = orig_fontset
sys.stdout.write("#")
sys.stdout.flush()
return depth
# LaTeX to HTML translation stuff:
def latex2html(node, source):
inline = isinstance(node.parent, nodes.TextElement)
latex = node['latex']
name = 'math-%s' % md5(latex).hexdigest()[-10:]
destdir = os.path.join(setup.app.builder.outdir, '_images', 'mathmpl')
if not os.path.exists(destdir):
os.makedirs(destdir)
dest = os.path.join(destdir, '%s.png' % name)
path = os.path.join(setup.app.builder.imgpath, 'mathmpl')
depth = latex2png(latex, dest, node['fontset'])
if inline:
cls = ''
else:
cls = 'class="center" '
if inline and depth != 0:
style = 'style="position: relative; bottom: -%dpx"' % (depth + 1)
else:
style = ''
return '<img src="%s/%s.png" %s%s/>' % (path, name, cls, style)
def setup(app):
setup.app = app
app.add_node(latex_math)
app.add_role('math', math_role)
# Add visit/depart methods to HTML-Translator:
def visit_latex_math_html(self, node):
source = self.document.attributes['source']
self.body.append(latex2html(node, source))
def depart_latex_math_html(self, node):
pass
# Add visit/depart methods to LaTeX-Translator:
def visit_latex_math_latex(self, node):
inline = isinstance(node.parent, nodes.TextElement)
if inline:
self.body.append('$%s$' % node['latex'])
else:
self.body.extend(['\\begin{equation}',
node['latex'],
'\\end{equation}'])
def depart_latex_math_latex(self, node):
pass
app.add_node(latex_math, html=(visit_latex_math_html,
depart_latex_math_html))
app.add_node(latex_math, latex=(visit_latex_math_latex,
depart_latex_math_latex))
app.add_role('math', math_role)
app.add_directive('math', math_directive,
True, (0, 0, 0), **options_spec)
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