在图例文字中使用matplotlib分散标记以及乳胶

Question

我有一个插图的情节。后者有一个传说，我想在其中使用matplotlib分散标记。我也希望能够在所有标签和传说的同时使用LaTeX。我提到这个的原因是因为我看了this thread，那里的解决方案对我不起作用。我会解释为什么波纹管。

下面是一个例子代码（对不起，我绘制功能，想不出任何东西）

# -*- 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() 

如果我与建议去here约乳胶和与

尝试

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

该图显示插图中没有图例。

相反，如果我决定实施统一的解决方案

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

我收到以下错误

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) 

这似乎是来自于事实，我现在用的乳胶，因为如果我注释掉

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

然后我得到一切正常，但没有LaTeX。 （我得到的这个圈子是黑色的，我还没有考虑是否有可能改变它的颜色）。尽管如此，我确实需要LaTeX，所以这对我并不好。

Answer 1

由于The Great, Big List of LaTeX Symbols告诉我们，\square是一个AMS符号。因此，为了使用它，你必须把\usepackage{amssymb}在你的序言，这是可以做到的

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