DISTCARTESIAN

The DISTCARTESIAN field specifier allows you to find documents that contain fields that define a point (X and Y coordinates) or region that is within a specified distance from a specified point.

You can specify the document position fields either as a pair of fields (corresponding to X and Y coordinate fields), or a single field that uses POINT or POLYGON definitions (in Well-known text format) to specify position information (for example, a unified GeospatialType field).

TIP:

If your document location fields contain regions (in Well-known text POLYGON format), the DISTCARTESIAN operator calculates distances from the geometric center of the region.

Format

FieldText=DISTCARTESIAN{coordX,coordY,dist}:POSITION
coordX The specified x coordinate.
coordY The specified y coordinate.
dist The distance in units from the specified x/y coordinates.
POSITION

The document field or fields that contain the position value. You can use one of the following options to specify location fields:

  • a single field. This field must contain a Well-known text format POINT or POLYGON definition (for example, POINT(x y)).
  • two fields, in the format X:Y, where X is the field that contains the x coordinate, and Y is the field that contains the y coordinate. You must specify the fields in the order x:y.

You can specify multiple options for the location fields, in form POSITION1:POSITION2:POSITION3, and so on. This form can include a mix of types (unified location fields and split latitude and longitude fields).

NOTE:

If you use multiple position fields or field pairs, IDOL Server cannot match documents where a pair of split geospatial fields occurs interleaved with other geospatial fields. For example, if you use X1:Y1:POSITION in your query, and these fields occur in a document in the order X1, POSITION, Y1, IDOL Server does not match that document.

In such cases, you can rewrite the query, in the form DISTCARTESIAN{...}:X1:Y1 OR DISTCARTESIAN{...}:POSITION

NOTE:

You can optimize this field specifier by configuring your coordinate fields with the GeospatialType or NumericType property types. If you want to use a single field with POINT or POLYGON definitions, you can optimize the field specifier only by using the unified GeospatialType property.

Examples

FieldText=DISTCARTESIAN{10,11,5}:X:Y

This example matches all documents whose (X,Y) position is within a distance of 5 units of the point (10,11). The position of a document in this example is contained in the fields X and Y.

FieldText=DISTCARTESIAN{10,11,5}:POSITION:X:Y

This example matches all documents whose (X,Y) position is within a distance of 5 units of the point (10,11). The position of a document in this example is contained in either the (unified) POSITION field, or the separate X and Y fields.


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