null+****@clear*****
null+****@clear*****
2012年 7月 11日 (水) 14:27:38 JST
HAYASHI Kentaro 2012-07-11 14:27:38 +0900 (Wed, 11 Jul 2012) New Revision: 1e93c1fb8447286c530c0be35dc9e4add29e0963 https://github.com/groonga/groonga/commit/1e93c1fb8447286c530c0be35dc9e4add29e0963 Log: doc: update the description Modified files: doc/source/functions/geo_distance.txt Modified: doc/source/functions/geo_distance.txt (+9 -8) =================================================================== --- doc/source/functions/geo_distance.txt 2012-07-11 14:19:27 +0900 (e27239d) +++ doc/source/functions/geo_distance.txt 2012-07-11 14:27:38 +0900 (cad82f1) @@ -45,11 +45,11 @@ between the coordinate of ``point1`` and the coordinate of ``point2``. Lets's learn about ``geo_distance`` usage with examples. This section shows simple usages. -Here are two schema definition and sample data to show usage. +Here are two schema definition and sample data to show the difference according to the usage. Those samples show how to calculate the value of distance between Tokyo and Sapporo. #. Using the column value of location for calculating the distance (``Stations`` table) -#. Using the explicitly specified value of location for calculating the distance (``Geo`` table) +#. Using the explicitly specified coodinates for calculating the distance (``Geo`` table) Using the column value of location ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -59,7 +59,7 @@ Here are a schema definition of ``Stations`` table and sample data to show usage .. groonga-command .. include:: ../example/functions/geo_distance_setup_location.log -There is a table named ``Stations``. ``Stations`` table has one column, ``location``. +This execution example creates a table named ``Stations`` which has one column named ``location``. ``location`` column stores the value of coordinate. The coordinate of Tokyo is stored as sample data. @@ -69,7 +69,8 @@ The coordinate of Tokyo is stored as sample data. This sample shows that ``geo_distance`` use the value of ``location`` column and the value of coordinate to calculate distance. -Note that the coordinate of Sapporo is "155047000x508862800". +The value ("155047000x508862800") passed to ``geo_distance`` as the second argument is +the coordinate of Sapporo. Using the explicitly specified value of location @@ -80,7 +81,7 @@ Here are a schema definition of ``Geo`` table and sample data to show usage. .. groonga-command .. include:: ../example/functions/geo_distance_setup_distance.log -There is a table named ``Geo``. ``Geo`` table has one column, ``distance``. +This execution example creates a table named ``Geo`` which has one column named ``distance``. ``distance`` column stores the value of distance. .. groonga-command @@ -154,7 +155,7 @@ You can specify the value of ``approximate_type`` by one of the followings. ............... This parameter require to approximate the geographical features -by square approximation. +by square approximation for calculating the distance. Since the value of distance is calculated by simple formula, you can calculate the value of distance fast. @@ -191,7 +192,7 @@ Here is a sample about calculating the value of distance with explicitly specifi ............... This parameter require to approximate the geographical features -by spherical approximation. +by spherical approximation for calculating the distance. It is slower than ``rectangle``, but the error of distance becomes smaller than ``rectangle``. @@ -207,7 +208,7 @@ Here is a sample about calculating the value of distance with column value. ............... This parameter require to approximate the geographical features -by ellipsoid approximation. +by ellipsoid approximation for calculating the distance. It uses the calculation of distance by the formula of Hubeny. It is slower than ``sphere``, but the error of distance becomes -------------- next part -------------- HTML$B$NE:IU%U%!%$%k$rJ]4I$7$^$7$?(B...下载
