如何在极坐标图周围添加环绕轴？

Question

我正在尝试弄清楚如何将轴附加到我的极坐标投影中。新添加的轴应该像环一样环绕在原始极轴上。

为此，我尝试在polar matplotlib 投影ax 上使用make_axes_locatable 创建的分隔符中的append_axes。

但是，没有“外部”选项或任何类似于带有 append_axes 参数的极坐标投影的选项。 而不是围绕轴的环，我在原来的轴下方得到了一个新轴（见图）。

是否有任何替代方法可以允许围绕现有极轴创建环形轴？

注意，我不想将它们添加到同一个斧头上，因为比例可能不同。

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import make_axes_locatable

plt.style.use("seaborn-white")
def synthesize(polar=False):
    fig = plt.figure()
    ax = fig.add_subplot(111, polar=polar)
    t = np.linspace(0,2*np.pi)
    r_sin = np.sin(t)
    r_cos = np.cos(t)
    for r in [r_sin, r_cos]:
        ax.scatter(t, r, c=r, s=t*100, edgecolor="white", cmap=plt.cm.magma_r)
        ax.scatter(t, -r, c=r, s=t*100, edgecolor="white", cmap=plt.cm.magma_r)
    ax.set_title("polar={}".format(polar),fontsize=15)
    ax.set_xticklabels([])
    return fig, ax, t

# Rectilinear
fig, ax, t = synthesize(polar=False)
# Here are the plot dimensions in response to the answer below
xlim = ax.get_xlim()
ylim = ax.get_ylim()
rlim = (ax.get_rmin(), ax.get_rmax())
print(xlim, ylim, rlim)
(0.0, 6.283185307179586) (0.0, 2.2437621373846617) (0.0, 2.2437621373846617)
# Encircling axis
divider = make_axes_locatable(ax)
ax_below = divider.append_axes("bottom", size="32.8%", pad=0.1)
ax_below.scatter(t, np.tan(t), c="black", edgecolor="white")

# Polar
fig, ax, t = synthesize(polar=True)
divider = make_axes_locatable(ax)
ax_below = divider.append_axes("bottom", size="32.8%", pad=0.1)
ax_below.scatter(t, np.tan(t), c="black", edgecolor="white")

Answer 1

您可能可以通过像这样调整set_rmax 和set_rorigin 来做一些事情：

import numpy as np
import matplotlib.pyplot as plt

plt.style.use("seaborn-white")
def synthesize(polar=False):
    fig = plt.figure()
    ax = fig.add_subplot(111, polar=polar)
    ax.set_rmax(30)
    t = np.linspace(0,2*np.pi)
    r_sin = np.sin(t)
    r_cos = np.cos(t)
    for r in [r_sin, r_cos]:
        ax.scatter(t, r, c=r, s=t*100, edgecolor="white", cmap=plt.cm.magma_r)
        ax.scatter(t, -r, c=r, s=t*100, edgecolor="white", cmap=plt.cm.magma_r)
    ax.set_title("polar={}".format(polar),fontsize=15)
    ax.set_xticklabels([])
    return fig, ax, t

# Polar
fig, ax, t = synthesize(polar=True)
ax_below = fig.add_subplot(111, polar=True, frameon=True)

# ax_below = divider.append_axes("bottom", size="32.8%", pad=0.1)
ax_below.scatter(t, np.tan(t), c="black", edgecolor="white")
ax_below.set_rorigin(-75)
ax_below.set_rmin(-25)
plt.show()