annotate #1720
Description
It is a bit cumbersome and unintuitive to use the annotate method with GeoAxes (see this discussion on stackoverflow).
To make the ax.annotate method more like the other GeoAxes methods (like plot, scatter, etc.), I suggest this thin wrapper:
class GeoAxes():
...
def annotate(self, *args, **kwargs):
crs = kwargs.pop('transform', self.projection)
transform = crs._as_mpl_transform(self)
kwargs['xycoords'] = transform
xy = kwargs['xy']
return self.annotate(*args, **kwargs)This way the transform keyword is used to properly construct the xycoords transform.
Example:
ax = plt.axes(projection=ccrs.PlateCarree())
ax.stock_img()
ny_lon, ny_lat = -75, 43
delhi_lon, delhi_lat = 77.23, 28.61
ax.plot(
[ny_lon, delhi_lon], [ny_lat, delhi_lat], '-bo', transform=ccrs.Geodetic(),
)
ax.annotate('New York', xy=(ny_lon, ny_lat), xytext=(-30, +15),
textcoords='offset points', ha='center', va='center',
arrowprops=dict(arrowstyle='->'),
transform=ccrs.Geodetic())
ax.annotate('Delhi', xy=(delhi_lon, delhi_lat), xytext=(+30, -15),
textcoords='offset points', ha='center', va='center',
arrowprops=dict(arrowstyle='->'),
transform=ccrs.Geodetic())