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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
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