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CSE 163

Geopandas�

Suh Young Choi�

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Announcements

Project proposals due Wednesday (May 14)

    • See Canvas assignment for more details
    • See Ed post #338 if you’re looking for partners

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Education Interview grades released

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Search grades released later tonight ☺

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Education resubmissions close on Thursday (May 15)

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This Time

  • Geospatial data
  • Using Geopandas

Last Time

  • Data Settings
  • Object-Oriented Programming
  • Classes

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Geospatial Data

  • Simply put, maps!
  • Represents places in the world and accompanying data

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Geopandas

  • Exactly like pandas, but with an extra geometry column
  • Files typically end in .shp
  • Can be used for plotting
  • Types
    • GeoDataFrame
    • GeoSeries

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Geopandas

  • Exactly like pandas, but with an extra geometry column
  • Files typically end in .shp
  • Can be used for plotting
  • Types
    • GeoDataFrame
    • GeoSeries

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import geopandas as gpd

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df = gpd.read_file('data_file.shp')

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df.plot(column='some_col', legend=True)

plt.savefig('plot.png')

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Matplotlib

  • Default plots gets plotted on a global figure (like a canvas)
    • Multiple plots would overwrite each other
  • You have to do extra work to get more information on the same set of axes.

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fig, ax = plt.subplots()

<plot1>(ax=ax)

<plot2>(ax=ax)

fig.savefig('plot_together.png')

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fig, [ax1, ax2] = plt.subplots(1, 2) # nrows, ncols

<plot1>(ax=ax1)

<plot2>(ax=ax2)

fig.savefig('plot_separate.png')

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Matplotlib

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fig

ax1

ax2

fig, [ax1, ax2] = plt.subplots(1, 2) # nrows, ncols

<plot1>(ax=ax1)

<plot2>(ax=ax2)

fig.savefig('plot_separate.png')

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Matplotlib

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fig

ax1

ax2

fig, [ax1, ax2] = plt.subplots(1, 2) # nrows, ncols

<plot1>(ax=ax1)

<plot2>(ax=ax2)

fig.savefig('plot_separate.png')

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Matplotlib

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fig

ax1

ax2

fig, [ax1, ax2] = plt.subplots(1, 2) # nrows, ncols

<plot1>(ax=ax1)

<plot2>(ax=ax2)

fig.savefig('plot_separate.png')

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Jupyter time!

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Before Next Time

  • Work on Project Proposals

Next Time

  • Two special Geopandas functions

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