From cf93a0193b9448f23737f4dad2de5bb1485899f1 Mon Sep 17 00:00:00 2001 From: andrewxhill Date: Wed, 20 Apr 2016 15:20:27 -0400 Subject: [PATCH] docs stub --- doc/methods.md | 176 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 176 insertions(+) create mode 100644 doc/methods.md diff --git a/doc/methods.md b/doc/methods.md new file mode 100644 index 0000000..1cae40f --- /dev/null +++ b/doc/methods.md @@ -0,0 +1,176 @@ +# Measures + +Measures Services allow users to access geospatial measures for analysis workflows. Measures are used by sending an identifier or a geometry (Point or Polygon) and receiving back a measure or absolute value for that location. Every measure contained in the Data Catalog can be accessed through the CartoDB Editor. + +Below are the methods. For detailed information for accessing any measures, see the catalog here, [Catalog PDF](http://cartodb.github.io/bigmetadata/index.html) + +## OBS_GetUSCensusMeasure(point_geometry, measure_name); + +The ```OBS_GetUSCensusMeasure(point_geometry, measure_name)``` method returns a measure based on a subset of the US Census variables at a point location. 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. + +#### Arguments + +Name |Description +--- | --- +geom | 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'). +normalize | for measures that are are **sums** (e.g. population) the default normalization is 'area' and response comes back as a rate per square kilometer. Other options are 'denominator', which will use the denominator specified in the + +#### Returns + +A JSON object 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' +``` + +Get a measure at a single point location + +```SQL +SELECT * FROM json_each(OBS_GetMeasure(CDB_LatLng(40.7, -73.9), 'Male Population')) +``` + + + +## 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. + +#### Arguments + +Name |Description +--- | --- +geom | a WGS84 polygon 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'). +normalize | for measures that are are **sums** (e.g. population) the default normalization is 'none' and response comes back as a raw value. Other options are 'denominator', which will use the denominator specified in the [Data Catalog](http://cartodb.github.io/bigmetadata/index.html) (optional) + +#### Returns + +A JSON object 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 polygons in your table + +```SQL +UPDATE tablename SET local_male_population = OBS_GetUSCensusMeasure(the_geom, 'Male Population') -> 'value' +``` + +Get a measure at a single polygon + +```SQL +SELECT * FROM json_each(OBS_GetMeasure(ST_Buffer(CDB_LatLng(40.7, -73.9),0.001), 'Male Population')) +``` + + + +## OBS_GetMeasure(point_geometry, measure_id); + +The ```OBS_GetMeasure(point_geometry, measure_id)``` method returns any Data Observatory measure at a point location. + +#### Arguments + +Name |Description +--- | --- +geom | a WGS84 point geometry (the_geom) +measure_id | a measure identifier from the Data Observatory ([see available measures](http://cartodb.github.io/bigmetadata/index.html)) +normalize | for measures that are are **sums** (e.g. population) the default normalization is 'area' and response comes back as a rate per square kilometer. Other options are 'denominator', which will use the denominator specified in the [Data Catalog](http://cartodb.github.io/bigmetadata/index.html) and 'none' which will return a raw value. (optional) + +#### Returns + +A JSON object 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_GetMeasure(the_geom, '"us.census.acs".B08134006') -> 'value' +``` + +Get a measure at a single point location + +```SQL +SELECT * FROM json_each(OBS_GetMeasure(CDB_LatLng(40.7, -73.9), '"us.census.acs".B08134006')) +``` + + + + +## OBS_GetMeasure(polygon_geometry, measure_id); + +The ```OBS_GetMeasure(polygon_geometry, measure_id)``` method returns any Data Observatory measure calculated within a polygon. + +#### Arguments + +Name |Description +--- | --- +geom | a WGS84 polygon geometry (the_geom) +measure_id | a measure identifier from the Data Observatory ([see available measures](http://cartodb.github.io/bigmetadata/index.html)) +normalize | for measures that are are **sums** (e.g. population) the default normalization is 'none' and response comes back as a raw value. Other options are 'denominator', which will use the denominator specified in the [Data Catalog](http://cartodb.github.io/bigmetadata/index.html) (optional) + +#### Returns + +A JSON object 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 polygons in your table + +```SQL +UPDATE tablename SET local_male_population = OBS_GetMeasure(the_geom, '"us.census.acs".B08134006') -> 'value' +``` + +Get a measure within a polygon + +```SQL +SELECT * FROM json_each(OBS_GetMeasure(ST_Buffer(CDB_LatLng(40.7, -73.9),0.001), '"us.census.acs".B08134006')) +``` + + + +--- + +# Boundaries + +# Discovery