rSPARCS (version 0.1.1)

pick.cases: Select cases within certain distance around a site

Description

Identify the closest site (e.g. monitoring sites) for each case, and select cases within certain distance around a site, e.g. 15 miles buffer.

Usage

pick.cases(data,long.case,lat.case,long.sites,lat.sites,radius)

Value

which.site

the closest site to the case.

minDIST

the distance of the case to the closest site; in the same unit as "radius".

Select

an indicator of whether a case was within the buffer.

Arguments

data

a data.frame containing the coordinates of cases.

long.case

the name of variable in the data indicating the longitude of cases.

lat.case

the name of variable in the data indicating the latitude of cases.

long.sites

a numeric vector containing the longitude of sites.

lat.sites

a numeric vector containing the latitude of sites.

radius

radius of the buffer, e.g."15 miles", "20 kms".

Details

Not limited to hospital data, but also applicable to other surveillance data.

References

Zhang W, Lin S, Hopke PK, et al. Triggering of cardiovascular hospital admissions by fine particle concentrations in New York state: Before, during, and after implementation of multiple environmental policies and a recession. Environ. Pollut. [electronic article]. 2018;242:1404–1416.

Examples

set.seed(2018)
data=data.frame(Patient=1:100,lat=rnorm(100,41,0.5),long=rnorm(100,-76,1))

long.monitor=c(-73.75464,-78.80953,-73.902,-73.82153,-77.54817)
lat.monitor=c(42.64225,42.87691,40.81618,40.73614,43.14618)

data.out=pick.cases(data,long.case="long",lat.case="lat",
long.sites=long.monitor,lat.sites=lat.monitor,radius="30 miles")
data.out