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- $center
$center¶
-
$center
¶ New in version 1.4.
The
$center
operator specifies a circle for a geospatial$geoWithin
query. The query returns legacy coordinate pairs that are within the bounds of the circle. The operator does not return GeoJSON objects.The query calculates distances using flat (planar) geometry.
The
2d
geospatial index supports the$center
operator.To use the
$center
operator, specify an array that contains:- The grid coordinates of the circle’s center point
- The circle’s radius, as measured in the units used by the coordinate system
Important
If you use longitude and latitude, specify longitude first.
Use the following syntax:
The following example query returns all documents that have coordinates that exist within the circle centered on
[ -74 , 40.74 ]
and with a radius of10
:Changed in version 2.2.3: Applications can use
$center
without having a geospatial index. However, geospatial indexes support much faster queries than the unindexed equivalents. Before 2.2.3, a geospatial index must exist on a field holding coordinates before using any of the geospatial query operators.