How to Plot glyphs over a Google Map by using Bokeh Library in Python
The bokeh library is used for plotting glyphs over a Google map. A glyph is a hieroglyphic symbol or a character. For using Google Maps in Bokeh, we can use the gmap() function of the bokeh.plotting class.
- google_api_key: It is a key of the Google API
- map_options: GmapOptions, that is, the configuration which is specific to the Google map
- active_drag: It is a dragging tool that has to be initially active.
- active_inspect: It is an inspecting tool that has to be initially active.
- active_scroll: It is a scrolling tool that has to be initially active.
- active_tap: It is a tapping tool that has to be initially active.
- title: It is the title of the Google map.
- tools: These are tools with which the plot should start.
- x_axis_label: It is used for labelling the x-axis
- x_axis_location: It is a location of the x-axis
- x_minor_ticks: These are the number of minor ticks between adjacent x-axis major ticks
- y_axis_label: It is used for labelling the y-axis
- y_axis_location: It is a location of the y-axis
- y_minor_ticks: These are the number of minor ticks between adjacent y-axis major ticks
It will return an object of the class GMap
- lat: It is used for the latitude where the Google map is to be centred.
- lng: It is used for longitude where the Google map is to be centred.
- map_type: It defines the type of Google maps to use for the plot. Here are the four types of maps available:
- name: It is the name for the Google map.
- scale_control: It defines whether the Google map should display its distance scale control.
- styles: It is used for defining the style of map to be used for the plot.
- subscribed_events: The is used for defining the list of events that are subscribed to by Python callbacks.
- tags: These are the tags linked with the Google map model.
- tilt: It is used for tilting the angle of the map.
- zoom: It is an initial zoom level of the Google map.
- apply_theme: It is a theme of the model.
It returns an object of the class GMapOptions
Steps for plotting glyphs over a Google map:
Step 1: Import the following modules and libraries:
- gmap from bokeh.plotting
- ColumnDataSource from bokeh.models
- GmapOptions from bokeh.models
- output_file from bokeh.io
- show from bokeh.io
Step 2: Create a file for storing the model by using the output_file()
Step 3: Configure Google map by using GMapOptions()
Step 4: Generate a Google map object by using the gmap()
Step 5: Define the coordinates of the glyphs y using the ColumnDataSource()
Step 6: Generate the glyphs on the above created object of Google Maps.
Step 7: Display the output of Google Maps by using the show()
In this tutorial, we have discussed how we can plot glyphs over a Google Map by using the Bokeh library in Python.