Kentaro Hayashi
null+****@clear*****
Tue Jul 4 14:47:50 JST 2017
Kentaro Hayashi 2017-07-04 14:47:50 +0900 (Tue, 04 Jul 2017) New Revision: 67b350391eb1fdee89e41e7c43609787e3eb4a04 https://github.com/groonga/groonga/commit/67b350391eb1fdee89e41e7c43609787e3eb4a04 Merged 9d192b5: Merge pull request #727 from kenhys/doc-math-abs Message: doc: add math_abs document Added files: doc/source/reference/functions/math_abs.rst Added: doc/source/reference/functions/math_abs.rst (+80 -0) 100644 =================================================================== --- /dev/null +++ doc/source/reference/functions/math_abs.rst 2017-07-04 14:47:50 +0900 (79cfd46) @@ -0,0 +1,80 @@ +.. -*- rst -*- + +.. highlightlang:: none + +.. groonga-command +.. database: math_abs + +``math_abs`` +=============== + +Summary +------- + +.. versionadded:: 7.0.4 + +``math_abs`` returns the absolute value of value. + +To enable this function, register ``functions/math`` plugin by following the command:: + + plugin_register functions/math + +Syntax +------ + +``math_abs`` requires one argument - ``target``. + +:: + + math_abs(target) + +Usage +----- + +Here is a schema definition and sample data. + +Sample schema: + +.. groonga-command +.. plugin_register functions/math +.. include:: ../../example/reference/functions/math_abs/usage_setup_schema.log +.. table_create Shops TABLE_HASH_KEY ShortText +.. column_create Shops from_station COLUMN_SCALAR Int32 +.. column_create Shops from_office COLUMN_SCALAR Int32 + +Sample data: + +.. groonga-command +.. include:: ../../example/reference/functions/math_abs/usage_setup_data.log +.. load --table Shops +.. [ +.. {"_key": "Coffee Shop", "from_station": 50}, +.. {"_key": "Donut & Coffee Shop", "from_station": 400}, +.. {"_key": "Cake & Coffee Shop", "from_station": 200} +.. ] + +Here is the simple usage of ``math_abs`` function which returns nearest shops from office. + +To detect nearest shops, we need to calculate distance. +If the distance of your office from station is 250 meters, you can calculate it by ``math_abs(250 - from_station)``. + +.. groonga-command +.. include:: ../../example/reference/functions/math_abs/nearest_shops.log +.. select Shops --filter true --output_columns '_key, from_office' --scorer 'from_office = math_abs(250 - from_station)' --sort_keys from_office + +By specifying ``--sort_keys from_office``, you can show nearest shops by ascending order. + +Parameters +---------- + +There is one required parameter, ``target``. + +``target`` +^^^^^^^^^^ + +Specifies a column of table that is specified by ``table`` parameter in ``select``. + +Return value +------------ + +``math_abs`` returns the absolute value of target column value. -------------- next part -------------- HTML����������������������������...Télécharger
