EOmaps_examples.rst

🗺 EOmaps examples

... a collection of examples that show how to create beautiful interactive maps.

Basic data visualization

There are 3 basic steps required to visualize your data:

1. Initialize a Maps-object with m = Maps()
2. Set the data and its specifications via m.set_data
3. Call m.plot_map() to generate the map!

|toggleStart|

.. literalinclude:: examples/example_basics.py

|toggleEnd|

Customize the appearance of the plot

• use m.set_plot_specs() to set the general appearance of the plot
• after creating the plot, you can access individual objects via m.figure.<...> … most importantly:
  • f : the matplotlib figure
  • ax, ax_cb, ax_cb_plot : the axes used for plotting the map, colorbar and histogram
  • gridspec, cb_gridspec : the matplotlib GridSpec instances for the plot and the colorbar
  • coll : the collection representing the data on the map

|toggleStart|

.. literalinclude:: examples/example_customization.py

|toggleEnd|

Data-classification and multiple Maps in a figure

• Create grids of maps via MapsGrid

• Classify your data via m.set_classify_specs(scheme, **kwargs)

  (using classifiers provided by the mapclassify module)
• Add individual callback functions to each subplot via

  m.cb.click.attach, m.cb.pick.attach
• Share events between Maps-objects of the MapsGrid via

  mg.share_click_events() and mg.share_pick_events()

|toggleStart|

.. literalinclude:: examples/example_multiple_maps.py

|toggleEnd|

Callbacks - turn your maps into interactive widgets

• Callback functions can easily be attached to the plot to turn it into an interactive plot-widget!

  • there’s a nice list of (customizable) pre-defined callbacks accessible via:

    m.cb.click, m.cb.pick, m.cb.keypress and m.cb.dynamic

    • use annotate (and clear_annotations) to create text-annotations
    • use mark (and clear_markers) to add markers
    • use peek_layer (and switch_layer) to compare multiple layers of data
    • ... and many more: plot, print_to_console, get_values, load ...

  • ... but you can also define a custom one and connect it via

    m.cb.click.attach(<my custom function>) (works also with pick and keypress)!

|toggleStart|

.. literalinclude:: examples/example_callbacks.py

|toggleEnd|

Overlays, markers and annotations

(… plot-generation might take a bit longer since overlays need to be downloaded first!)

• add basic overlays with m.add_overlay
• add static annotations / markers with m.add_annotation and m.add_marker
• use “connected” Maps-objects to get multiple interactive data-layers!

|toggleStart|

.. literalinclude:: examples/example_overlays.py

|toggleEnd|

The data displayed in the above gif is taken from:

• NaturalEarth (https://www.naturalearthdata.com/)

WebMap services and layer-switching

• add WebMap services using m.add_wms and m.add_wmts
• compare different data-layers and WebMap services using m.cb.click.peek_layer and m.cb.keypress.switch_layer

|toggleStart|

.. literalinclude:: examples/example_webmaps.py

|toggleEnd|

The data displayed in the above gif is taken from:

• Sentinel-1 Global Backscatter Model (https://researchdata.tuwien.ac.at/records/n2d1v-gqb91)
• OpenStreetMap hosted by Mundialis (https://www.mundialis.de/en/ows-mundialis/)

Vector data - interactive geometries

EOmaps can be used to assign callbacks to vektor-data (e.g. geopandas.GeoDataFrames).

• to make a GeoDataFrame pickable, first use m.add_gdf(picker_name="MyPicker")

  • now you can assign callbacks via m.cb.pick__MyPicker.attach... just as you would do with the ordinary m.cb.click or m.cb.pick callbacks

Note

For large datasets that are visualized as simple rectangles, ellipses etc. it is recommended to use EOmaps to visualize the data with m.plot_map() since the generation of the plot and the identification of the picked pixels will be much faster!

If the GeoDataFrame contains multiple different geometry types (e.g. Lines, Patches, etc.) a unique pick-collection will be assigned for each of the geometry types!

|toggleStart|

.. literalinclude:: examples/example_vector_data.py

|toggleEnd|

The data displayed in the above gif is taken from:

• NaturalEarth (https://www.naturalearthdata.com/)

Using Scalebars

EOmaps has a nice customizable scalebar feature!

• use s = m.add_scalebar(lon, lat, azim) to attach a scalebar to the plot
• once the scalebar is there, you can drag it around and change its properties via s.set_position, s.set_scale_props(), s.set_label_props() and s.set_patch_props()

Note

You can also simply drag the scalebar with the mouse!

• LEFT-click on it to make it interactive!
• RIGHT-click anywhere on the map to make it fixed again

There are also some useful keyboard shortcuts you can use while the scalebar is interactive

• use +/- to rotate the scalebar
• use alt + +/- to set the text-offset
• use the arrow-keys to increase the frame-widths
• use alt + arrow-keys to decrease the frame-widths
• use delete to remove the scalebar from the plot

|toggleStart|

.. literalinclude:: examples/example_scalebars.py

|toggleEnd|

The data displayed in the above gif is taken from:

• NaturalEarth (https://www.naturalearthdata.com/)

Data analysis widgets - Timeseries and histograms

Callback-functions can be used to trigger updates on other plots. This example shows how to use EOmaps to analyze a database that is associated with a map.

• create a grid of Maps objects and ordinary matplotlib axes via MapsGrid
• define a custom callback to update the plots if you click on the map

|toggleStart|

.. literalinclude:: examples/example_timeseries.py

|toggleEnd|

Data analysis widgets - Select 1D slices of a 2D dataset

Use custom callback functions to perform arbitrary tasks on the data when clicking on the map.

• Identify clicked row/col in a 2D dataset
• Highlight the found row and column using a new layer

(requires EOmaps >= v3.1.4)

|toggleStart|

.. literalinclude:: examples/example_row_col_selector.py

|toggleEnd|

Inset-maps - get a zoomed-in view on selected areas

Quickly create nice inset-maps to show details for specific regions.

• the location and extent of the inset can be defined in any given crs
  • (or as a geodesic circle with a radius defined in meters)
• the inset-map can have a different crs than the "parent" map

(requires EOmaps >= v4.1)

|toggleStart|

.. literalinclude:: examples/example_inset_maps.py

|toggleEnd|

Lines and Annotations

Draw lines defined by a set of anchor-points and add some nice annotations.

Connect the anchor-points via:

• geodesic lines
• straight lines
• reprojected straight lines defined in a given projection

(requires EOmaps >= v4.3.1)

|toggleStart|

.. literalinclude:: examples/example_lines.py

|toggleEnd|

Gridlines and Grid Labels

Draw custom grids and add grid labels.

(requires EOmaps >= v6.5)

|toggleStart|

.. literalinclude:: examples/example_gridlines.py

|toggleEnd|

Contour plots and Contour Levels

Use the contour-shape to draw contour-plots of regular (or irregular data) or to indicate contour-levels on top of other plots.

(requires EOmaps >= v7.1)

|toggleStart|

.. literalinclude:: examples/example_contour.py

|toggleEnd|