Matplotlib - mark_inset 使用不同边缘的轴标记

Question

我想在一个子图中绘制一个阻尼随机游动的时间序列，然后在第二个子图中放大它。我知道mark_inset来自matplotlib，它工作得很好。到目前为止，我掌握的代码是：

from mpl_toolkits.axes_grid1.inset_locator import mark_inset
from astroML.time_series import generate_damped_RW

fig = plt.figure()
ax = fig.add_subplot(111)
ax0 = fig.add_subplot(211)
ax1 = fig.add_subplot(212)

ax.set_ylabel('Brightness[mag]')
ax.yaxis.labelpad=30
ax.spines['top'].set_color('none')
ax.spines['bottom'].set_color('none')
ax.spines['left'].set_color('none')
ax.spines['right'].set_color('none')
ax.tick_params(labelcolor='w', top='off', bottom='off', left='off',
               right='off')

t = np.linspace(0, 5000, 100000)
data = generate_damped_RW(t, tau=100, xmean=20, z=0, SFinf=0.3,
                          random_state=1)
ax0.scatter(t, data, s=0.5)
ax0.text(1, 1, r'$E(m) = %.2f, \sigma(m) = %.2f$'%(np.mean(data),
                                                   np.std(data)),
         verticalalignment='top', horizontalalignment='right',
         transform=ax0.transAxes, fontsize=23)

mask = (t > 370) & (t < 470)
ax1.set_xlabel('Time[years]')
ax1.scatter(t[mask], data[mask], s=0.5)

mark_inset(ax0, ax1, loc1=2, loc=1, fc='none')

这样就形成了这样的情节：

这几乎是我想要的，除了连接两个子图的线从第一个子图的框的上边缘开始。在第二个子图中，有没有可能让它们从下两个边开始，而最后还是在上两个边结束？我要做什么才能达到这个目的？在

Answer 1

^{}有两个参数loc1和{}来设置两个连接器的位置。然后，这些位置对于长方体和和插入轴是相同的。在

但是，我们可以向mark_inset函数添加两个新参数，以设置连接器的开始和结束的不同位置。在

import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1.inset_locator import TransformedBbox, BboxPatch, BboxConnector 
import numpy as np

fig, (ax, axins) = plt.subplots(nrows=2)

x = np.linspace(0,6*np.pi)
y = np.sin(x)
ax.plot(x,y)
axins.plot(x,y)
axins.set_xlim((2*np.pi, 2.5*np.pi))
axins.set_ylim((0, 1))

# draw a bbox of the region of the inset axes in the parent axes and
# connecting lines between the bbox and the inset axes area
# loc1, loc2 : {1, 2, 3, 4} 
def mark_inset(parent_axes, inset_axes, loc1a=1, loc1b=1, loc2a=2, loc2b=2, **kwargs):
    rect = TransformedBbox(inset_axes.viewLim, parent_axes.transData)

    pp = BboxPatch(rect, fill=False, **kwargs)
    parent_axes.add_patch(pp)

    p1 = BboxConnector(inset_axes.bbox, rect, loc1=loc1a, loc2=loc1b, **kwargs)
    inset_axes.add_patch(p1)
    p1.set_clip_on(False)
    p2 = BboxConnector(inset_axes.bbox, rect, loc1=loc2a, loc2=loc2b, **kwargs)
    inset_axes.add_patch(p2)
    p2.set_clip_on(False)

    return pp, p1, p2

mark_inset(ax, axins, loc1a=1, loc1b=4, loc2a=2, loc2b=3, fc="none", ec="crimson") 

plt.draw()
plt.show()

Answer 2

不幸的是，^{}总是要连接相同的角（即右下角总是要连接到右下角，等等）。在

我们可以创建自己的函数来模仿mark_inset函数，将两个底角与inset中的两个上角连接起来（下面的代码中是custom_mark_inset）。在

这将使用^{}面片在主轴上绘制长方体，并使用^{}实例绘制轴之间的连接线。在

from mpl_toolkits.axes_grid1.inset_locator import mark_inset
#from astroML.time_series import generate_damped_RW
import matplotlib.pyplot as plt
import matplotlib.patches as patches
import numpy as np

fig = plt.figure()
ax = fig.add_subplot(111)
ax0 = fig.add_subplot(211)
ax1 = fig.add_subplot(212)

ax.set_ylabel('Brightness[mag]')
ax.yaxis.labelpad=30
ax.spines['top'].set_color('none')
ax.spines['bottom'].set_color('none')
ax.spines['left'].set_color('none')
ax.spines['right'].set_color('none')
ax.tick_params(labelcolor='w', top='off', bottom='off', left='off',
               right='off')

t = np.linspace(0, 5000, 10000)
#data = generate_damped_RW(t, tau=100, xmean=20, z=0, SFinf=0.3,
#                          random_state=1)
## Fake some data
data = np.sin(t/800.) + 20.

ax0.scatter(t, data, s=0.5)
ax0.text(1, 1, r'$E(m) = %.2f, \sigma(m) = %.2f$'%(np.mean(data),
                                                   np.std(data)),
         verticalalignment='top', horizontalalignment='right',
         transform=ax0.transAxes, fontsize=23)

mask = (t > 370) & (t < 470)
ax1.set_xlabel('Time[years]')
ax1.scatter(t[mask], data[mask], s=0.5)

def custom_mark_inset(axA, axB, fc='None', ec='k'):
    xx = axB.get_xlim()
    yy = axB.get_ylim()

    xy = (xx[0], yy[0])
    width = xx[1] - xx[0]
    height = yy[1] - yy[0]

    pp = axA.add_patch(patches.Rectangle(xy, width, height, fc=fc, ec=ec))

    p1 = axA.add_patch(patches.ConnectionPatch(
        xyA=(xx[0], yy[0]), xyB=(xx[0], yy[1]),
        coordsA='data', coordsB='data',
        axesA=axA, axesB=axB))

    p2 = axA.add_patch(patches.ConnectionPatch(
        xyA=(xx[1], yy[0]), xyB=(xx[1], yy[1]),
        coordsA='data', coordsB='data',
        axesA=axA, axesB=axB))

    return pp, p1, p2

pp, p1, p2 = custom_mark_inset(ax0, ax1)

plt.show()