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r"""
This module supports embedded TeX expressions in matplotlib via dvipng
and dvips for the raster and postscript backends. The tex and
dvipng/dvips information is cached in ~/.matplotlib/tex.cache for reuse between
sessions
Requirements:
* latex
* \*Agg backends: dvipng>=1.6
* PS backend: psfrag, dvips, and Ghostscript>=8.60
Backends:
* \*Agg
* PS
* PDF
For raster output, you can get RGBA numpy arrays from TeX expressions
as follows::
texmanager = TexManager()
s = ('\TeX\ is Number '
'$\displaystyle\sum_{n=1}^\infty\frac{-e^{i\pi}}{2^n}$!')
Z = texmanager.get_rgba(s, fontsize=12, dpi=80, rgb=(1,0,0))
To enable tex rendering of all text in your matplotlib figure, set
:rc:`text.usetex` to True.
"""
import copy
import glob
import hashlib
import logging
import os
from pathlib import Path
import re
import subprocess
import numpy as np
import matplotlib as mpl
from matplotlib import _png, cbook, dviread, rcParams
_log = logging.getLogger(__name__)
class TexManager(object):
"""
Convert strings to dvi files using TeX, caching the results to a directory.
"""
cachedir = mpl.get_cachedir()
if cachedir is not None:
texcache = os.path.join(cachedir, 'tex.cache')
Path(texcache).mkdir(parents=True, exist_ok=True)
else:
# Should only happen in a restricted environment (such as Google App
# Engine). Deal with this gracefully by not creating a cache directory.
texcache = None
# Caches.
rgba_arrayd = {}
grey_arrayd = {}
postscriptd = property(mpl.cbook.deprecated("2.2")(lambda self: {}))
pscnt = property(mpl.cbook.deprecated("2.2")(lambda self: 0))
serif = ('cmr', '')
sans_serif = ('cmss', '')
monospace = ('cmtt', '')
cursive = ('pzc', r'\usepackage{chancery}')
font_family = 'serif'
font_families = ('serif', 'sans-serif', 'cursive', 'monospace')
font_info = {
'new century schoolbook': ('pnc', r'\renewcommand{\rmdefault}{pnc}'),
'bookman': ('pbk', r'\renewcommand{\rmdefault}{pbk}'),
'times': ('ptm', r'\usepackage{mathptmx}'),
'palatino': ('ppl', r'\usepackage{mathpazo}'),
'zapf chancery': ('pzc', r'\usepackage{chancery}'),
'cursive': ('pzc', r'\usepackage{chancery}'),
'charter': ('pch', r'\usepackage{charter}'),
'serif': ('cmr', ''),
'sans-serif': ('cmss', ''),
'helvetica': ('phv', r'\usepackage{helvet}'),
'avant garde': ('pag', r'\usepackage{avant}'),
'courier': ('pcr', r'\usepackage{courier}'),
'monospace': ('cmtt', ''),
'computer modern roman': ('cmr', ''),
'computer modern sans serif': ('cmss', ''),
'computer modern typewriter': ('cmtt', '')}
_rc_cache = None
_rc_cache_keys = (
('text.latex.preamble', 'text.latex.unicode', 'text.latex.preview',
'font.family') + tuple('font.' + n for n in font_families))
def __init__(self):
if self.texcache is None:
raise RuntimeError('Cannot create TexManager, as there is no '
'cache directory available')
Path(self.texcache).mkdir(parents=True, exist_ok=True)
ff = rcParams['font.family']
if len(ff) == 1 and ff[0].lower() in self.font_families:
self.font_family = ff[0].lower()
elif isinstance(ff, str) and ff.lower() in self.font_families:
self.font_family = ff.lower()
else:
_log.info('font.family must be one of (%s) when text.usetex is '
'True. serif will be used by default.',
', '.join(self.font_families))
self.font_family = 'serif'
fontconfig = [self.font_family]
for font_family in self.font_families:
font_family_attr = font_family.replace('-', '_')
for font in rcParams['font.' + font_family]:
if font.lower() in self.font_info:
setattr(self, font_family_attr,
self.font_info[font.lower()])
_log.debug('family: %s, font: %s, info: %s',
font_family, font, self.font_info[font.lower()])
break
else:
_log.debug('%s font is not compatible with usetex.',
font_family)
else:
_log.info('No LaTeX-compatible font found for the %s font '
'family in rcParams. Using default.', font_family)
setattr(self, font_family_attr, self.font_info[font_family])
fontconfig.append(getattr(self, font_family_attr)[0])
# Add a hash of the latex preamble to self._fontconfig so that the
# correct png is selected for strings rendered with same font and dpi
# even if the latex preamble changes within the session
preamble_bytes = self.get_custom_preamble().encode('utf-8')
fontconfig.append(hashlib.md5(preamble_bytes).hexdigest())
self._fontconfig = ''.join(fontconfig)
# The following packages and commands need to be included in the latex
# file's preamble:
cmd = [self.serif[1], self.sans_serif[1], self.monospace[1]]
if self.font_family == 'cursive':
cmd.append(self.cursive[1])
self._font_preamble = '\n'.join(
[r'\usepackage{type1cm}'] + cmd + [r'\usepackage{textcomp}'])
def get_basefile(self, tex, fontsize, dpi=None):
"""
Return a filename based on a hash of the string, fontsize, and dpi.
"""
s = ''.join([tex, self.get_font_config(), '%f' % fontsize,
self.get_custom_preamble(), str(dpi or '')])
return os.path.join(
self.texcache, hashlib.md5(s.encode('utf-8')).hexdigest())
def get_font_config(self):
"""Reinitializes self if relevant rcParams on have changed."""
if self._rc_cache is None:
self._rc_cache = dict.fromkeys(self._rc_cache_keys)
changed = [par for par in self._rc_cache_keys
if rcParams[par] != self._rc_cache[par]]
if changed:
_log.debug('following keys changed: %s', changed)
for k in changed:
_log.debug('%-20s: %-10s -> %-10s',
k, self._rc_cache[k], rcParams[k])
# deepcopy may not be necessary, but feels more future-proof
self._rc_cache[k] = copy.deepcopy(rcParams[k])
_log.debug('RE-INIT\nold fontconfig: %s', self._fontconfig)
self.__init__()
_log.debug('fontconfig: %s', self._fontconfig)
return self._fontconfig
def get_font_preamble(self):
"""
Return a string containing font configuration for the tex preamble.
"""
return self._font_preamble
def get_custom_preamble(self):
"""Return a string containing user additions to the tex preamble."""
return '\n'.join(rcParams['text.latex.preamble'])
def make_tex(self, tex, fontsize):
"""
Generate a tex file to render the tex string at a specific font size.
Return the file name.
"""
basefile = self.get_basefile(tex, fontsize)
texfile = '%s.tex' % basefile
custom_preamble = self.get_custom_preamble()
fontcmd = {'sans-serif': r'{\sffamily %s}',
'monospace': r'{\ttfamily %s}'}.get(self.font_family,
r'{\rmfamily %s}')
tex = fontcmd % tex
if rcParams['text.latex.unicode']:
unicode_preamble = r"""
\usepackage[utf8]{inputenc}"""
else:
unicode_preamble = ''
s = r"""
\documentclass{article}
%s
%s
%s
\usepackage[papersize={72in,72in},body={70in,70in},margin={1in,1in}]{geometry}
\pagestyle{empty}
\begin{document}
\fontsize{%f}{%f}%s
\end{document}
""" % (self._font_preamble, unicode_preamble, custom_preamble,
fontsize, fontsize * 1.25, tex)
with open(texfile, 'wb') as fh:
if rcParams['text.latex.unicode']:
fh.write(s.encode('utf8'))
else:
try:
fh.write(s.encode('ascii'))
except UnicodeEncodeError as err:
_log.info("You are using unicode and latex, but have not "
"enabled the 'text.latex.unicode' rcParam.")
raise
return texfile
_re_vbox = re.compile(
r"MatplotlibBox:\(([\d.]+)pt\+([\d.]+)pt\)x([\d.]+)pt")
def make_tex_preview(self, tex, fontsize):
"""
Generate a tex file to render the tex string at a specific font size.
It uses the preview.sty to determine the dimension (width, height,
descent) of the output.
Return the file name.
"""
basefile = self.get_basefile(tex, fontsize)
texfile = '%s.tex' % basefile
custom_preamble = self.get_custom_preamble()
fontcmd = {'sans-serif': r'{\sffamily %s}',
'monospace': r'{\ttfamily %s}'}.get(self.font_family,
r'{\rmfamily %s}')
tex = fontcmd % tex
if rcParams['text.latex.unicode']:
unicode_preamble = r"""
\usepackage[utf8]{inputenc}"""
else:
unicode_preamble = ''
# newbox, setbox, immediate, etc. are used to find the box
# extent of the rendered text.
s = r"""
\documentclass{article}
%s
%s
%s
\usepackage[active,showbox,tightpage]{preview}
\usepackage[papersize={72in,72in},body={70in,70in},margin={1in,1in}]{geometry}
%% we override the default showbox as it is treated as an error and makes
%% the exit status not zero
\def\showbox#1%%
{\immediate\write16{MatplotlibBox:(\the\ht#1+\the\dp#1)x\the\wd#1}}
\begin{document}
\begin{preview}
{\fontsize{%f}{%f}%s}
\end{preview}
\end{document}
""" % (self._font_preamble, unicode_preamble, custom_preamble,
fontsize, fontsize * 1.25, tex)
with open(texfile, 'wb') as fh:
if rcParams['text.latex.unicode']:
fh.write(s.encode('utf8'))
else:
try:
fh.write(s.encode('ascii'))
except UnicodeEncodeError as err:
_log.info("You are using unicode and latex, but have not "
"enabled the 'text.latex.unicode' rcParam.")
raise
return texfile
def _run_checked_subprocess(self, command, tex):
_log.debug(command)
try:
report = subprocess.check_output(command,
cwd=self.texcache,
stderr=subprocess.STDOUT)
except subprocess.CalledProcessError as exc:
raise RuntimeError(
'{prog} was not able to process the following string:\n'
'{tex!r}\n\n'
'Here is the full report generated by {prog}:\n'
'{exc}\n\n'.format(
prog=command[0],
tex=tex.encode('unicode_escape'),
exc=exc.output.decode('utf-8')))
_log.debug(report)
return report
def make_dvi(self, tex, fontsize):
"""
Generate a dvi file containing latex's layout of tex string.
Return the file name.
"""
if rcParams['text.latex.preview']:
return self.make_dvi_preview(tex, fontsize)
basefile = self.get_basefile(tex, fontsize)
dvifile = '%s.dvi' % basefile
if not os.path.exists(dvifile):
texfile = self.make_tex(tex, fontsize)
with cbook._lock_path(texfile):
self._run_checked_subprocess(
["latex", "-interaction=nonstopmode", "--halt-on-error",
texfile], tex)
for fname in glob.glob(basefile + '*'):
if not fname.endswith(('dvi', 'tex')):
try:
os.remove(fname)
except OSError:
pass
return dvifile
def make_dvi_preview(self, tex, fontsize):
"""
Generate a dvi file containing latex's layout of tex string.
It calls make_tex_preview() method and store the size information
(width, height, descent) in a separate file.
Return the file name.
"""
basefile = self.get_basefile(tex, fontsize)
dvifile = '%s.dvi' % basefile
baselinefile = '%s.baseline' % basefile
if not os.path.exists(dvifile) or not os.path.exists(baselinefile):
texfile = self.make_tex_preview(tex, fontsize)
report = self._run_checked_subprocess(
["latex", "-interaction=nonstopmode", "--halt-on-error",
texfile], tex)
# find the box extent information in the latex output
# file and store them in ".baseline" file
m = TexManager._re_vbox.search(report.decode("utf-8"))
with open(basefile + '.baseline', "w") as fh:
fh.write(" ".join(m.groups()))
for fname in glob.glob(basefile + '*'):
if not fname.endswith(('dvi', 'tex', 'baseline')):
try:
os.remove(fname)
except OSError:
pass
return dvifile
def make_png(self, tex, fontsize, dpi):
"""
Generate a png file containing latex's rendering of tex string.
Return the file name.
"""
basefile = self.get_basefile(tex, fontsize, dpi)
pngfile = '%s.png' % basefile
# see get_rgba for a discussion of the background
if not os.path.exists(pngfile):
dvifile = self.make_dvi(tex, fontsize)
self._run_checked_subprocess(
["dvipng", "-bg", "Transparent", "-D", str(dpi),
"-T", "tight", "-o", pngfile, dvifile], tex)
return pngfile
@mpl.cbook.deprecated("2.2")
def make_ps(self, tex, fontsize):
"""
Generate a postscript file containing latex's rendering of tex string.
Return the file name.
"""
basefile = self.get_basefile(tex, fontsize)
psfile = '%s.epsf' % basefile
if not os.path.exists(psfile):
dvifile = self.make_dvi(tex, fontsize)
self._run_checked_subprocess(
["dvips", "-q", "-E", "-o", psfile, dvifile], tex)
return psfile
@mpl.cbook.deprecated("2.2")
def get_ps_bbox(self, tex, fontsize):
"""
Return a list of PS bboxes for latex's rendering of the tex string.
"""
psfile = self.make_ps(tex, fontsize)
with open(psfile) as ps:
for line in ps:
if line.startswith('%%BoundingBox:'):
return [int(val) for val in line.split()[1:]]
raise RuntimeError('Could not parse %s' % psfile)
def get_grey(self, tex, fontsize=None, dpi=None):
"""Return the alpha channel."""
key = tex, self.get_font_config(), fontsize, dpi
alpha = self.grey_arrayd.get(key)
if alpha is None:
pngfile = self.make_png(tex, fontsize, dpi)
X = _png.read_png(os.path.join(self.texcache, pngfile))
self.grey_arrayd[key] = alpha = X[:, :, -1]
return alpha
def get_rgba(self, tex, fontsize=None, dpi=None, rgb=(0, 0, 0)):
"""Return latex's rendering of the tex string as an rgba array."""
if not fontsize:
fontsize = rcParams['font.size']
if not dpi:
dpi = rcParams['savefig.dpi']
r, g, b = rgb
key = tex, self.get_font_config(), fontsize, dpi, tuple(rgb)
Z = self.rgba_arrayd.get(key)
if Z is None:
alpha = self.get_grey(tex, fontsize, dpi)
Z = np.dstack([r, g, b, alpha])
self.rgba_arrayd[key] = Z
return Z
def get_text_width_height_descent(self, tex, fontsize, renderer=None):
"""Return width, height and descent of the text."""
if tex.strip() == '':
return 0, 0, 0
dpi_fraction = renderer.points_to_pixels(1.) if renderer else 1
if rcParams['text.latex.preview']:
# use preview.sty
basefile = self.get_basefile(tex, fontsize)
baselinefile = '%s.baseline' % basefile
if not os.path.exists(baselinefile):
dvifile = self.make_dvi_preview(tex, fontsize)
with open(baselinefile) as fh:
l = fh.read().split()
height, depth, width = [float(l1) * dpi_fraction for l1 in l]
return width, height + depth, depth
else:
# use dviread. It sometimes returns a wrong descent.
dvifile = self.make_dvi(tex, fontsize)
with dviread.Dvi(dvifile, 72 * dpi_fraction) as dvi:
page = next(iter(dvi))
# A total height (including the descent) needs to be returned.
return page.width, page.height + page.descent, page.descent