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- $centerSphere
$centerSphere¶
-
$centerSphere
¶ New in version 1.8.
The
$centerSphere
operator is the spherical equivalent of the$center
operator.$centerSphere
uses spherical geometry to define a circle for use by the$within
operator in geospatial queries.To define the bounds of a query using
$centerSphere
, you must specify:- The center point
- The angular distance in radians (distance along the surface of the earth).
Consider the following prototype:
The following example returns all documents within a 10 mile radius of longitude
88 W
and latitude30 N
. MongoDB converts the distance, 10 miles, to radians by dividing by the approximate radius of the earth, 3959 miles:Changed in version 2.2.3: Before 2.2.3, a geospatial index must exist on a field holding coordinates before using any of the geolocation query operators. After 2.2.3, applications may use geolocation query operators without having a geospatial index; however, geospatial indexes will support much faster geospatial queries than the unindexed equivalents.
Note
A geospatial index must exist on a field and the field must hold coordinates before you can use any of the geolocation query operators.