在圖例文本中與mattex一起使用matplotlib散布標記

Question

我有一個帶插圖的情節。 后者有一個圖例，我想在其文字中使用matplotlib散布標記。 我還希望能夠對所有標簽和圖例同時使用LaTeX。 我之所以提到這個原因是因為我查看了這個線程 ，而那里的解決方案對我來說卻行不通。 我將解釋為什么吼叫。

這是一個示例代碼（對我正在繪制的功能很抱歉，什么都沒想到）

# -*- coding: utf-8 -*-
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid.inset_locator import (inset_axes, InsetPosition, mark_inset)
from matplotlib import rc
rc('text', usetex=True)

N = 50
x = np.random.rand(N)
y = np.random.rand(N)

fig, ax1 = plt.subplots()

ax1.scatter(x, np.cos(x), color = 'blue', marker = "D", s=47.5, label = r'$\cos$')
ax1.scatter(y, np.sin(y), color = 'cyan', marker = "*", alpha = 0.85, label = r'$\sin$')
ax1box = ax1.get_position()
x_value = -0.13
y_value = 0.675
legend=ax1.legend(loc = (ax1box.x0 + x_value, ax1box.y0 + y_value), handletextpad=0.1, prop={'size':8})
frame = legend.get_frame()
frame.set_alpha(0)
frame.set_linewidth(0)

ax2 = plt.axes([0.5,0.5,0.5,0.5])
ip = InsetPosition(ax1, [0.55,0,0.45,0.40])
ax2.set_axes_locator(ip)
ax2.scatter(x, np.tan(x), color = 'gray', marker = "v", s=15, label = r'Insert blue square marker here')
ax2.scatter(y, np.log(y)+1, color = 'brown', marker = "4", s=15, label = r'Insert cyan star marker here')
ax2.xaxis.tick_top()
ax2.xaxis.set_label_position('top')
ax2.yaxis.tick_right()
legend2=ax2.legend(loc = 'lower right', handletextpad=0.1, prop={'size':7})
frame2 = legend2.get_frame()
frame2.set_alpha(0)
frame2.set_linewidth(0)

plt.show()

如果我要遵循此處有關LaTeX的建議並嘗試

ax2.scatter(x, np.tan(x), color = 'gray', marker = "v", s=15, label = r'$\square$')

該圖顯示插圖中沒有圖例。

相反，如果我決定實施unicode解決方案

ax2.scatter(x, np.tan(x), color = 'gray', marker = "v", s=15, label = '●')

我收到以下錯誤

Exception in Tkinter callback
Traceback (most recent call last):
  File "/usr/lib/python3.5/tkinter/__init__.py", line 1562, in __call__
    return self.func(*args)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/backends/backend_tkagg.py", line 280, in resize
    self.show()
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/backends/backend_tkagg.py", line 351, in draw
    FigureCanvasAgg.draw(self)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/backends/backend_agg.py", line 464, in draw
    self.figure.draw(self.renderer)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/artist.py", line 63, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/figure.py", line 1144, in draw
    renderer, self, dsu, self.suppressComposite)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/image.py", line 139, in _draw_list_compositing_images
    a.draw(renderer)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/artist.py", line 63, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/axes/_base.py", line 2426, in draw
    mimage._draw_list_compositing_images(renderer, self, dsu)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/image.py", line 139, in _draw_list_compositing_images
    a.draw(renderer)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/artist.py", line 63, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/legend.py", line 471, in draw
    bbox = self._legend_box.get_window_extent(renderer)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/offsetbox.py", line 269, in get_window_extent
    w, h, xd, yd, offsets = self.get_extent_offsets(renderer)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/offsetbox.py", line 391, in get_extent_offsets
    for c in self.get_visible_children()]
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/offsetbox.py", line 391, in <listcomp>
    for c in self.get_visible_children()]
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/offsetbox.py", line 262, in get_extent
    w, h, xd, yd, offsets = self.get_extent_offsets(renderer)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/offsetbox.py", line 462, in get_extent_offsets
    for c in self.get_visible_children()]
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/offsetbox.py", line 462, in <listcomp>
    for c in self.get_visible_children()]
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/offsetbox.py", line 262, in get_extent
    w, h, xd, yd, offsets = self.get_extent_offsets(renderer)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/offsetbox.py", line 391, in get_extent_offsets
    for c in self.get_visible_children()]
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/offsetbox.py", line 391, in <listcomp>
    for c in self.get_visible_children()]
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/offsetbox.py", line 262, in get_extent
    w, h, xd, yd, offsets = self.get_extent_offsets(renderer)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/offsetbox.py", line 462, in get_extent_offsets
    for c in self.get_visible_children()]
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/offsetbox.py", line 462, in <listcomp>
    for c in self.get_visible_children()]
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/offsetbox.py", line 835, in get_extent
    bbox, info, d = self._text._get_layout(renderer)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/text.py", line 362, in _get_layout
    ismath=ismath)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/backends/backend_agg.py", line 230, in get_text_width_height_descent
    renderer=self)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/texmanager.py", line 676, in get_text_width_height_descent
    dvifile = self.make_dvi(tex, fontsize)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/texmanager.py", line 399, in make_dvi
    texfile = self.make_tex(tex, fontsize)
  File "/usr/local/lib/python3.5/dist-packages/matplotlib/texmanager.py", line 314, in make_tex
    fh.write(s.encode('ascii'))
UnicodeEncodeError: 'ascii' codec can't encode character '\u25cf' in position 226: ordinal not in range(128) 

這似乎來自我使用LaTeX的事實，就像我注釋掉一樣

# from matplotlib import rc
# rc('text', usetex=True)

然后，我一切正常，但是沒有LaTeX。 （好吧，我得到的圓圈是黑色的，我還沒有考慮是否可以更改其顏色）。 我確實想要LaTeX，所以這對我不好。

Answer 1

正如《乳膠符號的偉大清單》告訴我們的那樣， \\square是AMS符號。 因此，為了使用它，您必須在您的序言中放入\\usepackage{amssymb} ，可以使用

rc('text', usetex=True)
rc('text.latex', preamble=r'\usepackage{amssymb}')