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).
TIP: If your document location field contains any shape other than a point, IDOL calculates distances from the geometric center of the shape.
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:
|
NOTE: You can optimize this field specifier by configuring your coordinate fields with the
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.