Polar Projection PDF Issue

Python 3.4
Conda 3.18.3
Matplotlib 1.5.1
basemap 1.0.7
Adobe Reader XI

Trying to plot a polar projection with a custom shapefile results in an error when opening the PDF in Adobe Reader.

I am creating two orthographic projections (a southern and northern hemisphere).

basemaps.append(Basemap(projection='ortho', lon_0=270, lat_0=90., resolution='c', ax=axes[0]))
basemaps.append(Basemap(projection='ortho', lon_0=90, lat_0=-90., resolution='c', ax=axes[1]))

I then draw a full world shapefile on each projection:

basemap.readshapefile('Earth', 'globe')
...
plt.savefig('amaps.pdf')

Everything works fine here and both basemaps display with the proper lines and shapes drawn. However, when downloading the PDF and displaying it in Adobe Acrobat, you will get something like this:
amap.pdf (which looks fine if you view it in your browser, but try downloading it and opening it with Adobe Reader). We've determined that the problem arises when the coastline includes lon, lat pairs in the opposite hemisphere from the hemisphere that it is to be drawn in. So if you are drawing the southern hemisphere, you cannot read a shapefile that has lon, lat points in the norther hemisphere, and vise-versa.

Our workaround required creating two separate shapefiles, one for the northern hemisphere and one for the southern. So now it looks like this:

# drawing northern hemisphere
if polar and idx == 0:
    basemap.readshapefile('Earth_north', 'nh')
elif polar and idx == 1:
# drawing southern hemisphere
    basemap.readshapefile('Earth_south', 'sh')
# drawing all other projections
else:
    basemap.readshapefile('Earth', 'globe')

This works fine but shouldn't be necessary.

首先，使用提供的正射投影代码片段和 PDF，通过 Basemap.readshapefile 和 plt.savefig 重现该问题。检查 shapefile 处理和 PDF 输出路径，以查找跨越半球的几何图形。当在 Adobe Reader 中打开 PDF 时，一个覆盖整个世界的 shapefile 能够在两个半球中正确渲染，即表示完成。