Update methods.md

added OBS_GetUSCensusCategory(point, category)

doc/methods.md

@@ -45,7 +45,7 @@ Should add the SQL API call here too
 
 ## OBS_GetUSCensusMeasure(polygon_geometry, measure_name);
 
-The ```OBS_GetUSCensusMeasure(point_geometry, measure_name)``` method returns a measure based on a subset of the US Census variables within a given polygon. The ```OBS_GetUSCensusMeasure``` method is limited to only a subset of all measures that are available in the Data Observatory, to access the full list, use the ```OBS_GetMeasure``` method below.
+The ```OBS_GetUSCensusMeasure(point_geometry, measure_name)``` method returns a measure based on a subset of the US Census variables within a given polygon. The ```OBS_GetUSCensusMeasure``` method is limited to only a subset of all measures that are available in the Data Observatory, to access the full list, use the ```OBS_GetUSCensusMeasure``` method below.
 
 #### Arguments
 
@@ -81,6 +81,43 @@ SELECT OBS_GetMeasure(ST_Buffer(CDB_LatLng(40.7, -73.9),0.001), 'Male Population
 Should add the SQL API call here too
 -->
 
+
+## 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')
+```
+
+<!--
+Should add the SQL API call here too
+-->
+
 ## OBS_GetMeasure(point_geometry, measure_id);
 
 The ```OBS_GetMeasure(point_geometry, measure_id)``` method returns any Data Observatory measure at a point location.