在 Matplotlib 中，我们可以使用 mathtext 作为标记来渲染字符串$ ..... $ (参考文献1 https://matplotlib.org/3.2.1/api/markers_api.html)
有什么方法可以将此文本封装在圆形或矩形框或任何不同的形状中吗？类似于如图所示的注册符号here https://maxcdn.icons8.com/Share/icon/p1em/Business/registered_trademark1600.png
I want to use this marker on a plot as shown below:
该图中使用了文本“$T$”，我希望文本包含在圆形或矩形中。
As suggested in the comments of the answer, I have plotted a square marker of a bit larger size before the text marker. This resolved the issue.
The final figure is shown below:
编辑：最简单的方法是简单地将补丁放置在与标记相同的位置，成为所需的“框架”。只要确保他们有一个较低的zorder这样它们就不会覆盖数据点。
更复杂的方法如下：
你可以打补丁。这是我用来制作自定义问号的示例：
import matplotlib as mpl
import matplotlib.pyplot as plt
import numpy as np
import matplotlib.markers as m
fig, ax = plt.subplots()
lim = -5.8, 5.7
ax.set(xlim = lim, ylim = lim)
marker_obj = m.MarkerStyle('$?$') #Here you place your letter
path = marker_obj.get_path().transformed(marker_obj.get_transform())
path._vertices = np.array(path._vertices)*8 #To make it larger
patch = mpl.patches.PathPatch(path, facecolor="cornflowerblue", lw=2)
ax.add_patch(patch)
def translate_verts(patch, i=0, j=0, z=None):
patch._path._vertices = patch._path._vertices + [i, j]
def rescale_verts(patch, factor = 1):
patch._path._vertices = patch._path._vertices * factor
#translate_verts(patch, i=-0.7, j=-0.1)
circ = mpl.patches.Arc([0,0], 11, 11,
angle=0.0, theta1=0.0, theta2=360.0,
lw=10, facecolor = "cornflowerblue",
edgecolor = "black")
ax.add_patch(circ)#One of the rings around the questionmark
circ = mpl.patches.Arc([0,0], 10.5, 10.5,
angle=0.0, theta1=0.0, theta2=360.0,
lw=10, edgecolor = "cornflowerblue")
ax.add_patch(circ)#Another one of the rings around the question mark
circ = mpl.patches.Arc([0,0], 10, 10,
angle=0.0, theta1=0.0, theta2=360.0,
lw=10, edgecolor = "black")
ax.add_patch(circ)
if __name__ == "__main__":
ax.axis("off")
ax.set_position([0, 0, 1, 1])
fig.canvas.draw()
#plt.savefig("question.png", dpi=40)
plt.show()
编辑，第二个答案： 创建由其他补丁组成的自定义补丁：
import matplotlib as mpl
import matplotlib.pyplot as plt
import numpy as np
import mpl_toolkits.mplot3d.art3d as art3d
class PlanetPatch(mpl.patches.Circle):
"""
This class combines many patches to make a custom patch
The best way to reproduce such a thing is to read the
source code for all patches you plan on combining.
Also make use of ratios as often as possible to maintain
proportionality between patches of different sizes"""
cz = 0
def __init__(self, xy, radius,
color = None, linewidth = 20,
edgecolor = "black", ringcolor = "white",
*args, **kwargs):
ratio = radius/6
mpl.patches.Circle.__init__(self, xy, radius,
linewidth = linewidth*ratio,
color = color,
zorder = PlanetPatch.cz,
*args, **kwargs)
self.set_edgecolor(edgecolor)
xy_ringcontour = np.array(xy)+[0, radius*-0.2/6]
self.xy_ringcontour = xy_ringcontour - np.array(xy)
self.ring_contour = mpl.patches.Arc(xy_ringcontour,
15*radius/6, 4*radius/6,
angle =10, theta1 = 165,
theta2 = 14.5,
fill = False,
linewidth = 65*linewidth*ratio/20,
zorder = 1+PlanetPatch.cz)
self.ring_inner = mpl.patches.Arc(xy_ringcontour,
15*radius/6, 4*radius/6,
angle = 10, theta1 = 165 ,
theta2 = 14.5,fill = False,
linewidth = 36*linewidth*ratio/20,
zorder = 2+PlanetPatch.cz)
self.top = mpl.patches.Wedge([0,0], radius, theta1 = 8,
theta2 = 192,
zorder=3+PlanetPatch.cz)
self.xy_init = xy
self.top._path._vertices=self.top._path._vertices+xy
self.ring_contour._edgecolor = self._edgecolor
self.ring_inner.set_edgecolor(ringcolor)
self.top._facecolor = self._facecolor
def add_to_ax(self, ax):
ax.add_patch(self)
ax.add_patch(self.ring_contour)
ax.add_patch(self.ring_inner)
ax.add_patch(self.top)
def translate(self, dx, dy):
self._center = self.center + [dx,dy]
self.ring_inner._center = self.ring_inner._center +[dx, dy]
self.ring_contour._center = self.ring_contour._center + [dx,dy]
self.top._path._vertices = self.top._path._vertices + [dx,dy]
def set_xy(self, new_xy):
"""As you can see all patches have different ways
to have their positions updated"""
new_xy = np.array(new_xy)
self._center = new_xy
self.ring_inner._center = self.xy_ringcontour + new_xy
self.ring_contour._center = self.xy_ringcontour + new_xy
self.top._path._vertices += new_xy - self.xy_init
fig = plt.figure(figsize=(6, 6))
ax = fig.add_subplot()
lim = -8.5, 8.6
ax.set(xlim = lim, ylim = lim,
facecolor = "black")
planets = []
colors = mpl.colors.cnames
colors = [c for c in colors]
for x in range(100):
xy = np.random.randint(-7, 7, 2)
r = np.random.randint(1, 15)/30
color = np.random.choice(colors)
planet = PlanetPatch(xy, r, linewidth = 20,
color = color,
ringcolor = np.random.choice(colors),
edgecolor = np.random.choice(colors))
planet.add_to_ax(ax)
planets.append(planet)
fig.canvas.draw()
#plt.savefig("planet.png", dpi=10)
plt.show()