|
|
# -*- coding: utf-8 -*-
|
|
|
"""Tools for handling LaTeX.
|
|
|
|
|
|
Authors:
|
|
|
|
|
|
* Brian Granger
|
|
|
"""
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Copyright (C) 2010-2011, IPython Development Team.
|
|
|
#
|
|
|
# Distributed under the terms of the Modified BSD License.
|
|
|
#
|
|
|
# The full license is in the file COPYING.txt, distributed with this software.
|
|
|
#-----------------------------------------------------------------------------
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Imports
|
|
|
#-----------------------------------------------------------------------------
|
|
|
|
|
|
from StringIO import StringIO
|
|
|
from base64 import encodestring
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Tools
|
|
|
#-----------------------------------------------------------------------------
|
|
|
|
|
|
|
|
|
def latex_to_png(s, encode=False):
|
|
|
"""Render a LaTeX string to PNG using matplotlib.mathtext.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
s : str
|
|
|
The raw string containing valid inline LaTeX.
|
|
|
encode : bool, optional
|
|
|
Should the PNG data bebase64 encoded to make it JSON'able.
|
|
|
"""
|
|
|
from matplotlib import mathtext
|
|
|
|
|
|
mt = mathtext.MathTextParser('bitmap')
|
|
|
f = StringIO()
|
|
|
mt.to_png(f, s, fontsize=12)
|
|
|
bin_data = f.getvalue()
|
|
|
if encode:
|
|
|
bin_data = encodestring(bin_data)
|
|
|
return bin_data
|
|
|
|
|
|
|
|
|
_data_uri_template_png = """<img src="data:image/png;base64,%s" alt=%s />"""
|
|
|
|
|
|
def latex_to_html(s, alt='image'):
|
|
|
"""Render LaTeX to HTML with embedded PNG data using data URIs.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
s : str
|
|
|
The raw string containing valid inline LateX.
|
|
|
alt : str
|
|
|
The alt text to use for the HTML.
|
|
|
"""
|
|
|
base64_data = latex_to_png(s, encode=True)
|
|
|
return _data_uri_template_png % (base64_data, alt)
|
|
|
|
|
|
|
|
|
# From matplotlib, thanks to mdboom. Once this is in matplotlib releases, we
|
|
|
# will remove.
|
|
|
def math_to_image(s, filename_or_obj, prop=None, dpi=None, format=None):
|
|
|
"""
|
|
|
Given a math expression, renders it in a closely-clipped bounding
|
|
|
box to an image file.
|
|
|
|
|
|
*s*
|
|
|
A math expression. The math portion should be enclosed in
|
|
|
dollar signs.
|
|
|
|
|
|
*filename_or_obj*
|
|
|
A filepath or writable file-like object to write the image data
|
|
|
to.
|
|
|
|
|
|
*prop*
|
|
|
If provided, a FontProperties() object describing the size and
|
|
|
style of the text.
|
|
|
|
|
|
*dpi*
|
|
|
Override the output dpi, otherwise use the default associated
|
|
|
with the output format.
|
|
|
|
|
|
*format*
|
|
|
The output format, eg. 'svg', 'pdf', 'ps' or 'png'. If not
|
|
|
provided, will be deduced from the filename.
|
|
|
"""
|
|
|
from matplotlib import figure
|
|
|
# backend_agg supports all of the core output formats
|
|
|
from matplotlib.backends import backend_agg
|
|
|
from matplotlib.font_manager import FontProperties
|
|
|
from matplotlib.mathtext import MathTextParser
|
|
|
|
|
|
if prop is None:
|
|
|
prop = FontProperties()
|
|
|
|
|
|
parser = MathTextParser('path')
|
|
|
width, height, depth, _, _ = parser.parse(s, dpi=72, prop=prop)
|
|
|
|
|
|
fig = figure.Figure(figsize=(width / 72.0, height / 72.0))
|
|
|
fig.text(0, depth/height, s, fontproperties=prop)
|
|
|
backend_agg.FigureCanvasAgg(fig)
|
|
|
fig.savefig(filename_or_obj, dpi=dpi, format=format)
|
|
|
|
|
|
return depth
|
|
|
|
|
|
|
