OWLIM-SE Geo-spatial Extensions

Version 1 by Dimitar Manov
on Mar 04, 2014 14:11.

compared with
Current by Vladimir Alexiev
on Aug 06, 2014 18:20.

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* ?lat{~}1~ <= ?plat <= ?lat{~}2~ \\
* ?long{~}1~ <= ?plong <= ?long{~}2~ \\
Using omgeo:within() is faster than the equivalent query using a conjunction of two inequalities. Even though ineqialities of numbers and dates use the Literal index and are relatively fast, each inequality may return a large number of results (falling in a horizontal, respectively vertical band), and joining them will take time. In contrast, omgeo:within() finds a smaller number of points (falling in the specified rectangle). \\
Note that the corners must be specified most westerly and southerly (first) and most northerly and easterly (second). Proper account is taken for rectangles that cross the \+/-180 degree meridian. \\
Constants are allowed for any of *?lat{*}{*}{~}1{~}* *?long{*}{*}{~}1{~}* *?lat{*}{*}{~}2{~}* *\*long{*}{*}{~}2{~}*, *?long{*}{*}{~}2{~}*, where latitude and longitude are specified in decimal degrees. If *?point* is unbound then bindings for all points within the rectangle will be produced. ||
|| Restrictions | Latitude is limited to the range \-90 (South) to \+90 (North) \\
Longitude is limited to the range \-180 (West) to \+180 (East) \\
Rectangle vertices must be specified in the order lower-left followed by upper-right ||
|| Examples | Find tunnels lying within a rectangle enclosing Tiyrol, Austria: \\
{noformat}PREFIX geo-pos: <http://www.w3.org/2003/01/geo/wgs84_pos#>
PREFIX geo-ont: <http://www.geonames.org/ontology#>