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pythonmatplotlibcartopy

Exclude Cartopy elements from Matplotlib legend

I'm plotting scatter points onto a map and seeing unwanted rectangles in my legend, despite the insertion of label='_nolegend_':

# import functions
import matplotlib.pyplot as plt
import cartopy.crs as ccrs
import cartopy.io.img_tiles as cimgt

# Create a Stamen terrain background instance
stamen_terrain = cimgt.Stamen('terrain-background')
fig = plt.figure(figsize = (10,10))
ax = fig.add_subplot(1, 1, 1, projection=stamen_terrain.crs, label='_nolegend_')

# Set range of map, stipulate zoom level
ax.set_extent([-122.7, -121.5, 37.15, 38.15], crs=ccrs.Geodetic())
ax.add_image(stamen_terrain, 12, label='_nolegend_')

# Add scatter point
ax.scatter(-122.4194, 37.7749, s=55, c='k', transform=ccrs.PlateCarree())    
ax.legend(('','','San Francisco'), loc = 3)
plt.show()

How to remove the rectangles, and just show the scatter point in the legend?

Legend has unwanted rectangles

Solution

  • The problem is that you set labels for each of the elements in the axes via ('','','San Francisco'). Instead just set the label to the scatter itself

    ax.scatter(..., label="Some City")
ax.legend(loc=3)

    Alternatively, if you don't want to give the scatter a label, you can pass the handle and label to the legend:

    sc = ax.scatter(...)    
ax.legend(handles=[sc], labels=['Some City'], loc = 3)