- lets_plot.geom_map(mapping=None, *, data=None, stat=None, position=None, show_legend=None, sampling=None, tooltips=None, map=None, map_join=None, **other_args)¶
Display polygons from a reference map.
Set of aesthetic mappings created by aes() function. Aesthetic mappings describe the way that variables in the data are mapped to plot “aesthetics”.
- datadict or DataFrame or GeoDataFrame
The data to be displayed in this layer. If None, the default, the data is inherited from the plot data as specified in the call to ggplot.
- statstr, default=’identity’
The statistical transformation to use on the data for this layer, as a string. Supported transformations: ‘identity’ (leaves the data unchanged), ‘count’ (counts number of points with same x-axis coordinate), ‘bin’ (counts number of points with x-axis coordinate in the same bin), ‘smooth’ (performs smoothing - linear default), ‘density’ (computes and draws kernel density estimate).
- positionstr or FeatureSpec
Position adjustment, either as a string (‘identity’, ‘stack’, ‘dodge’, …), or the result of a call to a position adjustment function.
- show_legendbool, default=True
False - do not show legend for this layer.
Result of the call to the sampling_xxx() function. Value None (or ‘none’) will disable sampling for this layer.
Result of the call to the layer_tooltips() function. Specifies appearance, style and content.
- mapGeoDataFrame or Geocoder
Data containing region boundaries (coordinates of polygon vertices on map).
- map_joinstr or list
Keys used to join map coordinates with data. First value in pair - column/columns in data. Second value in pair - column/columns in map.
Other arguments passed on to the layer. These are often aesthetics settings used to set an aesthetic to a fixed value, like color=’red’, fill=’blue’, size=3 or shape=21. They may also be parameters to the paired geom/stat.
Geom object specification.
geom_map() draws polygons which boundaries are specified by map parameter. Aesthetics of ploygons (fill etc.) are computed basing on input data and mapping (see data and mapping arguments).
geom_map() understands the following aesthetics:
alpha : transparency level of a layer. Understands numbers between 0 and 1.
color (colour) : color of a geometry lines. Can be continuous or discrete. For continuous value this will be a color gradient between two colors.
fill : color of a geometry internals. Can be continuous or discrete. For continuous value this will be a color gradient between two colors.
size : lines width. Defines line width.
linetype : type of the line. Codes and names: 0 = ‘blank’, 1 = ‘solid’, 2 = ‘dashed’, 3 = ‘dotted’, 4 = ‘dotdash’, 5 = ‘longdash’, 6 = ‘twodash’.
The data and map parameters of GeoDataFrame type support shapes Polygon and MultiPolygon.
The map parameter of Geocoder type implicitly invoke boundaries() function.
The conventions for the values of map_join parameter are as follows.
Joining data and GeoDataFrame object
Data has a column named ‘State_name’ and GeoDataFrame has a matching column named ‘state’:
Joining data and Geocoder object
Data has a column named ‘State_name’. The matching key in Geocoder is always ‘state’ (providing it is a state-level geocoder) and can be omitted:
Joining data by composite key
Joining by composite key works like in examples above, but instead of using a string for a simple key you need to use an array of strings for a composite key. The names in the composite key must be in the same order as in the US street addresses convention: ‘city’, ‘county’, ‘state’, ‘country’. For example, the data has columns ‘State_name’ and ‘County_name’. Joining with a 2-keys county level Geocoder object (the Geocoder keys ‘county’ and ‘state’ are omitted in this case):
1from lets_plot import * 2from lets_plot.geo_data import * 3LetsPlot.setup_html() 4country = geocode_countries('Italy').get_boundaries(resolution=6) 5ggplot() + geom_map(data=country)
The geodata is provided by © OpenStreetMap contributors and is made available here under the Open Database License (ODbL).