resolvers.rst

Built-in resolvers

By default, Carmen attempts to resolve tweet locations by three methods, in the following order:

1. Using the place resolver, which matches Twitter Places to known locations by name. This resolver takes two options:
   • allow_unknown_locations determines whether unknown Places are converted to locations that may be returned from resolution. By default, this option is False.
   • resolve_to_known_ancestor determines whether tweets with unknown Places are resolved to the nearest known ancestor location containing that Place. For example, an unknown city may be resolved to a known state- or provincial-level location. Such a backed-off location, unlike others returned from this resolver, may be superseded by more confident estimates from other resolvers. This option is only effective if allow_unknown_locations is False, and itself defaults to False.
2. Using the geocode resolver, which finds the known location nearest the tweet's geographic coordinates. This resolver takes a single option, max_distance, which specifies the maximum distance away from the coordinates, in miles, that the resolver will look for matching locations.
3. Using the profile resolver, which matches the "location" fields of tweet authors' user profiles to known locations by name. This resolver takes no options.

The :py:attr:`.resolution_method` attribute of each :py:class:`.Location` object, and the corresponding resolution_method key in the resulting JSON output, contain a string specifying the name of the resolver used to determine a tweet's location.