ws_metadata_2_pgdb: ws_metadata_2_pgdb() stores metadata of NOAA info into a...

In rabravo/ws2pgdb: Retrieves, manipulates, and stores data from NOAA, U.S.Census, and Epimodels.org. Uses location of weather stations (ws) to create a clustering of counties around the ws

Description

This function works in cascade with the all_coor_ws(). This function uses the mindate and maxdate returned from the rnoaa API data frame. Weather stations are described in terms of mindate, and maxdate dates, were weather data is available. Hence, given a particular variable (i.e. TMAX, TMIN, PRCP, etc), we are interested to retrieve the number of weather stations whose time window defined by the interval [mindate, maxdate] intersects and the length of the time window is maximum. Searching for answers online, it seems that this is a hard computing problem. It belongs to the set of problems defined as the 'Maximum Subset Intersection' problem which are close-related to the set cover problem studied in graph theory. The following function computes a resulting set using an heuristic described through the comments in the body of the function.

Usage

ws_metadata_2_pgdb(geoid, type, stations)

Arguments

geoid	FIPS number from census tables (tiger files)
type	Variable under investigation i.e. TMAX, TMIN, PRCP
stations	The universe of stations from the rnoaa API from where the new subset will be computed.

Value

function returns the name of the new table of the subset of weather stations with intersecting data

Note

Remember that all_coor_ws() returns a set of stations.

Examples

ghcnd    <- 'GHCND'
geoid    <- '12087'
type     <- 'TMAX'
stations <- as.data.frame( all_coor_ws( ghcnd, geoid, type) )
ws_metadata_2_pgdb( geoid, type, stations ) 

rabravo/ws2pgdb documentation built on May 26, 2019, 8:51 p.m.