aq_latest: Provides the latest value of each available parameter for...

In masalmon/ropenaq: Accesses Air Quality Data from the Open Data Platform OpenAQ

Provides the latest value of each available parameter for every location in the system.

Description

Provides the latest value of each available parameter for every location in the system.

Usage

aq_latest(
  country = NULL,
  city = NULL,
  location = NULL,
  parameter = NULL,
  has_geo = NULL,
  limit = 10000,
  latitude = NULL,
  longitude = NULL,
  radius = NULL,
  page = NULL
)

Arguments

country	Limit results by a certain country – a two-letters code see countries() for finding code based on name.
city	Limit results by a certain city.
location	Limit results by a certain location.
parameter	Limit to only a certain parameter (valid values are 'pm25', 'pm10', 'so2', 'no2', 'o3', 'co' and 'bc'). If no parameter is given, all parameters are retrieved.
has_geo	Filter out items that have or do not have geographic information.
limit	Change the number of results returned, max is 10000 by page. If no page value, then all results or limit * 100 (maximal number of pages) is returned.
latitude	Latitude of the center point (lat, lon) used to get measurements within a certain area.
longitude	Longitude of the center point (lat, lon) used to get measurements within a certain area.
radius	Radius (in meters) used to get measurements within a certain area, must be used with latitude and longitude
page	The page of the results to query (max 100).

Details

For queries involving a city or location argument, the URL-encoded name of the city/location (as in cityURL/locationURL), not its name, should be used. You can query any nested combination of country/location/city (level 1, 2 and 3), with only one value for each argument. If you write inconsistent combination such as city="Paris" and country="IN", an error message will be returned. If you write city="Delhi", you do not need to write the code of the country, unless one day there is a city with the same name in another country.

Value

A results data.frame (dplyr "tbl_df") with 11 columns:

• the name of the location ("location"),

• the city it is in ("city"),

• the code of country it is in ("country"),

• its longitude ("longitude") and latitude if available ("latitude"),

• the parameter ("parameter")

• the value of the measurement ("value")

• the last time and date at which the value was updated ("lastUpdated"),

• the unit of the measure ("unit")

• and finally an URL encoded version of the city name ("cityURL")

• and of the location name ("locationURL").

. and two attributes, a meta data.frame (dplyr "tbl_df") with 1 line and 5 columns:

• the API name ("name"),

• the license of the data ("license"),

• the website url ("website"),

• the queried page ("page"),

• the limit on the number of results ("limit"),

• the number of results found on the platform for the query ("found")

and a timestamp data.frame (dplyr "tbl_df") with the query time and the last time at which the data was modified on the platform.

Examples

## Not run: 
latest_chennai <- aq_latest(country='IN', city='Chennai')
latest_chennai
attr(latest_chennai, "meta")
attr(latest_chennai, "timestamp")
aq_latest(parameter='co')

## End(Not run)

masalmon/ropenaq documentation built on May 17, 2022, 4:43 a.m.