使用 cartopy 和 AxesGrid 时如何获得 "L" 形状的刻度标签

Question

我正在尝试按照 cartopy 文档 here 中显示的示例修改使用 cartopy + AxesGrid 的 Axes 的标记标签。但与示例不同的是，我只想要 "L" 形状的刻度标签，即最左边一列的垂直刻度标签和底行的水平刻度标签。

当我编辑任何轴的水平刻度标签时，该列中所有轴的水平刻度标签都会随之更改。同样对于垂直刻度标签和该行中的所有轴。（无论是否使用 cartopy，AxesGrid 都是如此，但在后一种情况下，我可以设置 label_mode='L' 而不必费心手动更改它们。）

我在 this gist 中创建了一个 MWE，转载于此：

import cartopy.crs as ccrs
from cartopy.mpl.geoaxes import GeoAxes
import matplotlib.pyplot as plt
import numpy as np
from mpl_toolkits.axes_grid1 import AxesGrid

fig = plt.figure()
projection = ccrs.PlateCarree()
axes_class = (GeoAxes,
              dict(map_projection=projection))

axgrid = AxesGrid(fig, 111, axes_class=axes_class,
                  nrows_ncols=(2, 2), 
                  axes_pad=0.3,
                  label_mode='')

for n, ax in enumerate(axgrid):
    ax.set_xticks(np.linspace(-180, 180, 5), crs=projection)
    ax.set_yticks(np.linspace(-90, 90, 5), crs=projection)

# Removing the xticklabels from the upper right corner panel
# also removes them from the lower right corner panel
axgrid[1].set_xticklabels([])

Answer 1

解决方案，感谢 @spencerkclark, is available in this gist 并在此处复制。

fig = plt.figure()
projection = ccrs.PlateCarree()
axes_class = (GeoAxes,
              dict(map_projection=projection))

axgrid = AxesGrid(fig, 111, axes_class=axes_class,
                  nrows_ncols=(2, 2), 
                  axes_pad=0.3,
                  label_mode='')

for n, ax in enumerate(axgrid):
    ax.set_xlim(-180, 180)
    ax.set_ylim(-90, 90)
    ax.set_xticks(np.linspace(-180, 180, 5), crs=projection)
    ax.set_yticks(np.linspace(-90, 90, 5), crs=projection)


# Make ticklabels on inner axes invisible
axes = np.reshape(axgrid, axgrid.get_geometry())
for ax in axes[:-1, :].flatten():
    ax.xaxis.set_tick_params(which='both', 
                             labelbottom=False, labeltop=False)

for ax in axes[:, 1:].flatten():
    ax.yaxis.set_tick_params(which='both', 
                             labelbottom=False, labeltop=False)

编辑：如果面板数量小于 nrows*ncols，则此逻辑失败，例如如果它是 4x2 网格但只有 7 个面板。以下也适用于这些情况：

def _hide_inner_ax_ticklabels(axgrid):
     """Produce 'L' shaped ticklabels: left row and bottom column only.

    Must do this manually when using axgrid + cartopy due to bug.
    See https://github.com/SciTools/cartopy/issues/939.
    """
    total_panels = axgrid._nrows * axgrid._ncols
    blank_panels = total_panels - axgrid.ngrids
    newgrid = np.concatenate([axgrid, [None]*blank_panels])
    axes = np.reshape(newgrid, axgrid.get_geometry())
    for ax in axes[:-1, :].flatten():
        try:
            ax.xaxis.set_tick_params(which='both', labelbottom=False, 
                                     labeltop=False)
        except AttributeError:
            pass

    for ax in axes[:, 1:].flatten():
        try:
            ax.yaxis.set_tick_params(which='both', labelbottom=False, 
                                     labeltop=False)
        except AttributeError:
            pass

使用 cartopy 和 AxesGrid 时如何获得 "L" 形状的刻度标签

How to get "L" shaped ticklabels when using cartopy and AxesGrid

python

matplotlib

cartopy