Postgresql earthdistance - 与半径的earth_box

请你能解释我earth_box函数的这种行为......或者我做错了什么？Postgresql earthdistance - 与半径的earth_box

数据使用

40.749276, -73.985643 = Empire State Building - is in my table 
40.689266, -74.044512 = Statue of Liberty - is my current position in select - 8324m far from Empire State Building

我的表从帝国大厦的雕像

=> select id, latitude, longitude, title from requests; 
id | latitude | longitude |   title 
----+-----------+------------+----------------------- 
    1 | 40.749276 | -73.985643 | Empire State Building

距离自由女神

=> SELECT id, latitude, longitude, title, earth_distance(ll_to_earth(40.689266, -74.044512), ll_to_earth(latitude, longitude)) as distance_from_current_location FROM requests ORDER BY distance_from_current_location ASC; 
id | latitude | longitude |   title   | distance_from_current_location 
----+-----------+------------+-----------------------+-------------------------------- 
    1 | 40.749276 | -73.985643 | Empire State Building |    8324.42998846164

我现在的位置是Libery雕像比8000米更远离帝国州Buildng，但选择返回行机智h id 1即使半径仅为5558m！你能解释我这种行为或者什么是错的？

=> SELECT id,latitude,longitude,title FROM requests WHERE earth_box(ll_to_earth(40.689266, -74.044512), 5558) @> ll_to_earth(requests.latitude, requests.longitude); 
id | latitude | longitude |   title 
----+-----------+------------+----------------------- 
    1 | 40.749276 | -73.985643 | Empire State Building

版本的扩展和PostgreSQL

=> \dx 
            List of installed extensions 
     Name  | Version | Schema |       Description 
---------------+---------+------------+-------------------------------------------------------------- cube   | 1.0  | public  | data type for multidimensional 
cubes earthdistance | 1.0  | public  | calculate great-circle 
distances on the surface of the Earth plpgsql  | 1.0  | 
pg_catalog | PL/pgSQL procedural language 

=> select version(); 
                   version 
-------------------------------------------------------------------------------------------------------------------------------------- PostgreSQL 9.4beta2 on x86_64-apple-darwin13.3.0, compiled by Apple 
LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn), 64-bit

感谢你 NOE

来源

2014-08-29 Noe

这里的问题是，earth_box得到法定英里。 8324.42998846164米接近5.172560986623845法定英里 Unit Converter

解决办法：半径转换为法定英里单位

earth_box(ll_to_earth(40.689266, -74.044512), 5558/1.609) //doesn't return results

earth_box(ll_to_earth(40.689266, -74.044512), 9000/1.609) //does.

来源

2014-11-03 09:53:53 Umpa

Postgresql earthdistance - 与半径的earth_box

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