distanceFilter property

double? distanceFilter

The minimum distance (measured in meters) a device must move horizontally before an update event is generated.

However, by default, distanceFilter is elastically auto-calculated by the plugin: When speed increases, distanceFilter increases; when speed decreases, so too does distanceFilter.

NOTE:

• To disable this behavior, configure disableElasticity:true.
• To control the scale of the automatic distanceFilter calculation, see elasticityMultiplier

distanceFilter is auto-scaled by rounding speed to the nearest 5 m/s and adding distanceFilter meters for each 5 m/s increment.

For example, at biking speed of 7.7 m/s with a configured distanceFilter: 30:

  rounded_speed = round(7.7, 5)
  => 10
  multiplier = rounded_speed / 5
  => 10 / 5 = 2
  adjusted_distance_filter = multiplier * distanceFilter
  => 2 * 30 = 60 meters

At highway speed of 27 m/s with a configured distanceFilter: 50:

  rounded_speed = round(27, 5)
  => 30
  multiplier = rounded_speed / 5
  => 30 / 5 = 6
  adjusted_distance_filter = multiplier * distanceFilter * elasticityMultiplier
  => 6 * 50 = 300 meters

Note the following real example of background-geolocation on highway 101 towards San Francisco as the driver slows down as he runs into slower traffic (locations become compressed as distanceFilter decreases)

Compare now background-geolocation in the scope of a city. In this image, the left-hand track is from a cab-ride, while the right-hand track is walking speed.

Implementation

double? distanceFilter;