使用文本作为路径#
TextPath 创建 Path，该路径是文本字符的轮廓。生成的路径可以例如用作图像的剪切路径。
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.cbook import get_sample_data
from matplotlib.image import BboxImage
from matplotlib.offsetbox import (AnchoredOffsetbox, AnnotationBbox,
AuxTransformBox)
from matplotlib.patches import PathPatch, Shadow
from matplotlib.text import TextPath
from matplotlib.transforms import IdentityTransform
class PathClippedImagePatch(PathPatch):
"""
The given image is used to draw the face of the patch. Internally,
it uses BboxImage whose clippath set to the path of the patch.
FIXME : The result is currently dpi dependent.
"""
def __init__(self, path, bbox_image, **kwargs):
super().__init__(path, **kwargs)
self.bbox_image = BboxImage(
self.get_window_extent, norm=None, origin=None)
self.bbox_image.set_data(bbox_image)
def set_facecolor(self, color):
"""Simply ignore facecolor."""
super().set_facecolor("none")
def draw(self, renderer=None):
# the clip path must be updated every draw. any solution? -JJ
self.bbox_image.set_clip_path(self._path, self.get_transform())
self.bbox_image.draw(renderer)
super().draw(renderer)
if __name__ == "__main__":
fig, (ax1, ax2) = plt.subplots(2)
# EXAMPLE 1
arr = plt.imread(get_sample_data("grace_hopper.jpg"))
text_path = TextPath((0, 0), "!?", size=150)
p = PathClippedImagePatch(text_path, arr, ec="k")
# make offset box
offsetbox = AuxTransformBox(IdentityTransform())
offsetbox.add_artist(p)
# make anchored offset box
ao = AnchoredOffsetbox(loc='upper left', child=offsetbox, frameon=True,
borderpad=0.2)
ax1.add_artist(ao)
# another text
for usetex, ypos, string in [
(False, 0.25, r"textpath supports mathtext"),
(True, 0.05, r"textpath supports \TeX"),
]:
text_path = TextPath((0, 0), string, size=20, usetex=usetex)
p1 = PathPatch(text_path, ec="w", lw=3, fc="w", alpha=0.9)
p2 = PathPatch(text_path, ec="none", fc="k")
offsetbox2 = AuxTransformBox(IdentityTransform())
offsetbox2.add_artist(p1)
offsetbox2.add_artist(p2)
ab = AnnotationBbox(offsetbox2, (0.95, ypos),
xycoords='axes fraction',
boxcoords="offset points",
box_alignment=(1., 0.),
frameon=False,
)
ax1.add_artist(ab)
ax1.imshow([[0, 1, 2], [1, 2, 3]], cmap=plt.cm.gist_gray_r,
interpolation="bilinear", aspect="auto")
# EXAMPLE 2
arr = np.arange(256).reshape(1, 256)
for usetex, xpos, string in [
(False, 0.25,
r"$\left[\sum_{n=1}^\infty\frac{-e^{i\pi}}{2^n}\right]$!"),
(True, 0.75,
r"$\displaystyle\left[\sum_{n=1}^\infty"
r"\frac{-e^{i\pi}}{2^n}\right]$!"),
]:
text_path = TextPath((0, 0), string, size=40, usetex=usetex)
text_patch = PathClippedImagePatch(text_path, arr, ec="none")
shadow1 = Shadow(text_patch, 1, -1, fc="none", ec="0.6", lw=3)
shadow2 = Shadow(text_patch, 1, -1, fc="0.3", ec="none")
# make offset box
offsetbox = AuxTransformBox(IdentityTransform())
offsetbox.add_artist(shadow1)
offsetbox.add_artist(shadow2)
offsetbox.add_artist(text_patch)
# place the anchored offset box using AnnotationBbox
ab = AnnotationBbox(offsetbox, (xpos, 0.5), box_alignment=(0.5, 0.5))
ax2.add_artist(ab)
ax2.set_xlim(0, 1)
ax2.set_ylim(0, 1)
plt.show()
---------------------------------------------------------------------------
RuntimeError Traceback (most recent call last)
Cell In[1], line 63
58 # another text
59 for usetex, ypos, string in [
60 (False, 0.25, r"textpath supports mathtext"),
61 (True, 0.05, r"textpath supports \TeX"),
62 ]:
---> 63 text_path = TextPath((0, 0), string, size=20, usetex=usetex)
65 p1 = PathPatch(text_path, ec="w", lw=3, fc="w", alpha=0.9)
66 p2 = PathPatch(text_path, ec="none", fc="k")
File /opt/hostedtoolcache/Python/3.12.8/x64/lib/python3.12/site-packages/matplotlib/textpath.py:355, in TextPath.__init__(self, xy, s, size, prop, _interpolation_steps, usetex)
352 self._cached_vertices = None
353 s, ismath = Text(usetex=usetex)._preprocess_math(s)
354 super().__init__(
--> 355 *text_to_path.get_text_path(prop, s, ismath=ismath),
356 _interpolation_steps=_interpolation_steps,
357 readonly=True)
358 self._should_simplify = False
File /opt/hostedtoolcache/Python/3.12.8/x64/lib/python3.12/site-packages/matplotlib/textpath.py:109, in TextToPath.get_text_path(self, prop, s, ismath)
73 """
74 Convert text *s* to path (a tuple of vertices and codes for
75 matplotlib.path.Path).
(...)
106 Also see `TextPath` for a more direct way to create a path from a text.
107 """
108 if ismath == "TeX":
--> 109 glyph_info, glyph_map, rects = self.get_glyphs_tex(prop, s)
110 elif not ismath:
111 font = self._get_font(prop)
File /opt/hostedtoolcache/Python/3.12.8/x64/lib/python3.12/site-packages/matplotlib/textpath.py:219, in TextToPath.get_glyphs_tex(self, prop, s, glyph_map, return_new_glyphs_only)
216 """Convert the string *s* to vertices and codes using usetex mode."""
217 # Mostly borrowed from pdf backend.
--> 219 dvifile = TexManager().make_dvi(s, self.FONT_SCALE)
220 with dviread.Dvi(dvifile, self.DPI) as dvi:
221 page, = dvi
File /opt/hostedtoolcache/Python/3.12.8/x64/lib/python3.12/site-packages/matplotlib/texmanager.py:292, in TexManager.make_dvi(cls, tex, fontsize)
290 with TemporaryDirectory(dir=cwd) as tmpdir:
291 tmppath = Path(tmpdir)
--> 292 cls._run_checked_subprocess(
293 ["latex", "-interaction=nonstopmode", "--halt-on-error",
294 f"--output-directory={tmppath.name}",
295 f"{texfile.name}"], tex, cwd=cwd)
296 (tmppath / Path(dvifile).name).replace(dvifile)
297 return dvifile
File /opt/hostedtoolcache/Python/3.12.8/x64/lib/python3.12/site-packages/matplotlib/texmanager.py:255, in TexManager._run_checked_subprocess(cls, command, tex, cwd)
251 raise RuntimeError(
252 f'Failed to process string with tex because {command[0]} '
253 'could not be found') from exc
254 except subprocess.CalledProcessError as exc:
--> 255 raise RuntimeError(
256 '{prog} was not able to process the following string:\n'
257 '{tex!r}\n\n'
258 'Here is the full command invocation and its output:\n\n'
259 '{format_command}\n\n'
260 '{exc}\n\n'.format(
261 prog=command[0],
262 format_command=cbook._pformat_subprocess(command),
263 tex=tex.encode('unicode_escape'),
264 exc=exc.output.decode('utf-8', 'backslashreplace'))
265 ) from None
266 _log.debug(report)
267 return report
RuntimeError: latex was not able to process the following string:
b'textpath supports \\\\TeX'
Here is the full command invocation and its output:
latex -interaction=nonstopmode --halt-on-error --output-directory=tmppgh67grx 152ce37b8c915b815a2d120ebb44ecad.tex
This is pdfTeX, Version 3.141592653-2.6-1.40.26 (TeX Live 2024) (preloaded format=latex)
restricted \write18 enabled.
entering extended mode
(./152ce37b8c915b815a2d120ebb44ecad.tex
LaTeX2e <2024-11-01> patch level 1
L3 programming layer <2024-12-09>
(/home/runner/.TinyTeX/texmf-dist/tex/latex/base/article.cls
Document Class: article 2024/06/29 v1.4n Standard LaTeX document class
(/home/runner/.TinyTeX/texmf-dist/tex/latex/base/size10.clo))
! LaTeX Error: File `type1cm.sty' not found.
Type X to quit or <RETURN> to proceed,
or enter new name. (Default extension: sty)
Enter file name:
! Emergency stop.
<read *>
l.7 \usepackage
{type1ec}^^M
No pages of output.
Transcript written on tmppgh67grx/152ce37b8c915b815a2d120ebb44ecad.log.
