diff --git a/doc/methods.md b/doc/methods.md index 8d52e44..43bf5a4 100644 --- a/doc/methods.md +++ b/doc/methods.md @@ -18,27 +18,24 @@ normalize | for measures that are are **sums** (e.g. population) the default nor #### Returns -A JSON object containing the following properties +A NUMERIC value containing the following properties Key | Description --- | --- value | the raw or normalized measure -name | the human readable name of the measure -description | a brief description of the measure -type | the data type (text, number, boolean) #### Example Add a Measure to an empty column based on point locations in your table ```SQL -UPDATE tablename SET local_male_population = OBS_GetUSCensusMeasure(the_geom, 'Male Population') -> 'value' +UPDATE tablename SET local_male_population = OBS_GetUSCensusMeasure(the_geom, 'Male Population') ``` Get a measure at a single point location ```SQL -SELECT * FROM json_each(OBS_GetUSCensusMeasure(CDB_LatLng(40.7, -73.9), 'Male Population')) +SELECT OBS_GetUSCensusMeasure(CDB_LatLng(40.7, -73.9), 'Male Population') ``` + + +## OBS_GetUSCensusCategory(point_geometry, measure_name); + +The ```OBS_GetUSCensusCategory(point_geometry, category_name)``` method returns a categorical measure based on a subset of the US Census variables at a point location. It requires a different function from ```OBS_GetUSCensusMeasure``` because this function will always return TEXT, whereas ```OBS_GetUSCensusMeasure``` will always returna NUMERIC value. + +#### Arguments + +Name |Description +--- | --- +point_geometry | a WGS84 point geometry (the_geom) +measure_name | a human readable string name of a US Census variable. The glossary of measure_names is [available below]('measure_name table'). +#### Returns + +A NUMERIC value containing the following properties + +Key | Description +--- | --- +value | the raw or normalized measure + +#### Example + +Add a Measure to an empty column based on point locations in your table + +```SQL +UPDATE tablename SET local_male_population = OBS_GetUSCensusCategory(the_geom, 'Spielman Singleton Category 10') +``` + +Get a measure at a single point location + +```SQL +SELECT OBS_GetUSCensusCategory(CDB_LatLng(40.7, -73.9), 'Spielman Singleton Category 10') ```