Introduction to GeoSetup class

import matplotlib
matplotlib.rcParams['savefig.dpi'] = 300
import geonum

Define domain

Create instance of Geosetup and specify domain by providing latitude and longitude of lower left (ll) and top right (tr) coordinates. Here, the summit region of the volcano Mt. Etna, Sicily, is used as an example.

from geonum.plot_helpers import plot_topo_contourf

domain = geonum.GeoSetup(id='Etna region (Sicily)',
                         lat_ll=37.5, lat_tr=38.0,
                         lon_ll=14.8, lon_tr=15.30,
                         topo_access_mode='srtm')

Add 2 GeoPoints to domain

Create GeoPoint at summit region of Mt. Etna and add to domain

etna = geonum.GeoPoint(latitude=37.751005,
                       longitude=14.993435,
                       altitude=3264.0,
                       name="Etna summit region")

domain.add_geo_point(etna)

Create GeoPoint for location of volcanological observatory at Mt. Etna and add to domain

observatory = geonum.GeoPoint(latitude=37.765755,
                              longitude=15.016696,
                              auto_topo_access=True,
                              name="Observatory")

domain.add_geo_point(observatory)

Retrieving SRTM data (this might take a while) ...
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Load topographic data using SRTM database

topo = domain.load_topo_data()

Retrieving SRTM data (this might take a while) ...
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Make a beautiful map of the GeoSetup

Note

the plotting features of geonum currently undergo revision, and thus, parts of the geonum plot API (geonum.plot_helpers) shown below is not finalised yet and may change. For details and updates related to the revision, see here: https://github.com/jgliss/geonum/issues/4

import matplotlib.pyplot as plt

# Initiate figure and cartopy GeoAxes for map plot
ax = geonum.plot_helpers.init_figure_with_geoaxes()

# Set x and y limits based on domain ranges
ax.set_xlim([domain.ll.longitude, domain.tr.longitude])
ax.set_ylim([domain.ll.latitude, domain.tr.latitude])

# Make a filled contour plot of the topography
ax, pdata = plot_topo_contourf(
    ax, # GeoAxes
    topo, # geonum.TopoData
    oceans_separate=True, # plot oceans in light blue
    levels=50, # number of vertical levels
    cmap='Oranges' # color map
)


# Add colorbar
cb = ax.figure.colorbar(pdata, label='Altitude [m]')

# Plot contour lines
ax.contour(
    *topo.init_mesh(),
    topo.data,
    levels=10,
    linestyles='--',
    linewidths=0.1,
    colors='k')

# Plot the 2 GeoPoints that were added to the GeoSetup
geonum.plot_helpers.plot_geopoint_into_map(ax,etna, color='w',
        marker='o',
        facecolor='none',
        s=16,
        annot_kwargs={'xytext': (etna.longitude, etna.latitude-0.05)})

geonum.plot_helpers.plot_geopoint_into_map(ax,observatory, color='w',
        marker='o',
        facecolor='none',
        s=16)

# Set title
ax.set_title(domain.id)

ax = geonum.plot_helpers.set_map_ticks(ax)
plt.show()