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Backport PR #2582: Fix displaying history when output cache is disabled....
Backport PR #2582: Fix displaying history when output cache is disabled. Previously, disabling the output cache disabled all history. These were separated, but the `%hist` magic was left with an unnecessary check, where if the output cache was disabled, it would refuse to work. Closes gh-2581

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latextools.py
181 lines | 4.9 KiB | text/x-python | PythonLexer
# -*- coding: utf-8 -*-
"""Tools for handling LaTeX.
Authors:
* Brian Granger
"""
#-----------------------------------------------------------------------------
# Copyright (C) 2010 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
import os
import tempfile
import shutil
import subprocess
from IPython.utils.process import find_cmd, FindCmdError
#-----------------------------------------------------------------------------
# Tools
#-----------------------------------------------------------------------------
def latex_to_png(s, encode=False, backend='mpl'):
"""Render a LaTeX string to PNG.
Parameters
----------
s : str
The raw string containing valid inline LaTeX.
encode : bool, optional
Should the PNG data bebase64 encoded to make it JSON'able.
backend : {mpl, dvipng}
Backend for producing PNG data.
None is returned when the backend cannot be used.
"""
if backend == 'mpl':
f = latex_to_png_mpl
elif backend == 'dvipng':
f = latex_to_png_dvipng
else:
raise ValueError('No such backend {0}'.format(backend))
bin_data = f(s)
if encode and bin_data:
bin_data = encodestring(bin_data)
return bin_data
def latex_to_png_mpl(s):
try:
from matplotlib import mathtext
except ImportError:
return None
mt = mathtext.MathTextParser('bitmap')
f = StringIO()
mt.to_png(f, s, fontsize=12)
return f.getvalue()
def latex_to_png_dvipng(s):
try:
find_cmd('latex')
find_cmd('dvipng')
except FindCmdError:
return None
try:
workdir = tempfile.mkdtemp()
tmpfile = os.path.join(workdir, "tmp.tex")
dvifile = os.path.join(workdir, "tmp.dvi")
outfile = os.path.join(workdir, "tmp.png")
with open(tmpfile, "w") as f:
f.write(_latex_header)
f.write(s)
f.write(_latex_footer)
subprocess.check_call(
["latex", "-halt-on-errror", tmpfile], cwd=workdir,
stdout=subprocess.PIPE, stderr=subprocess.PIPE)
subprocess.check_call(
["dvipng", "-T", "tight", "-x", "1500", "-z", "9",
"-bg", "transparent", "-o", outfile, dvifile], cwd=workdir,
stdout=subprocess.PIPE, stderr=subprocess.PIPE)
with open(outfile) as f:
bin_data = f.read()
finally:
shutil.rmtree(workdir)
return bin_data
_latex_header = r'''
\documentclass{article}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{amssymb}
\usepackage{bm}
\pagestyle{empty}
\begin{document}
'''
_latex_footer = r'\end{document}'
_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)
if base64_data:
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