BIASDISTSPHERICAL

The BIASDISTSPHERICAL field specifier allows you to boost the score of any document according to its distance from a specified point using spherical coordinates (latitude/longitude).

Format

FieldText=BIASDISTSPHERICAL{lat,long,range,maxboost}:LOCATION

lat	The specified latitude. Specify latitude positions south of the equator as negative.
long	The specified longitude. Specify longitude positions west of the Greenwich Meridian as negative.
range	The distance in kilometers from the specified latitude and longitude.
maxboost	The maximum percentage to boost the result.
LOCATION	The document field or fields that contain the location value. You can use one of the following options to specify location fields: a single field. This field must contain a supported well-known text geometric object. See Supported Well-Known Text Geometric Objects. This field must be a unified GeospatialType field. two fields, in the format LATFIELD:LONGFIELD, where LATFIELD is the field that contains the latitude value, and LONGFIELD is the field that contains the longitude value. You must specify the fields in the order latitude:longitude. The fields must be NumericType or GeospatialType.

Example

FieldText=BIASDISTSPHERICAL{52.2,0.1,100,7}:LAT:LONG

FieldText=BIASDISTSPHERICAL{52.2,0.1,100,7}:LOCATION

In these examples, all documents within 100 kilometers of the point (lat,long)=(52.2,0.1) are given a relevance boost. The maximum boost of 7 percent is given to documents at the given point. The boost decreases linearly down to 0 boost at 100 kilometers.

In the first example, the location data is stored in two document fields, LAT and LONG. In the second example, the location data is stored in a single LOCATION field.