Process road emissions data — process

The process_nei() function imports and cleans raw road emissions data, returning a single SpatVector object.

NEI data comprises multiple csv files where emissions of 50+ pollutants are recorded at county level. With raw data files, this function will join a combined table of NEI data and county boundary, then perform a spatial join to target locations.

Usage

process_nei(path = NULL, county = NULL, year = c(2017, 2020), ...)

Arguments

path: character(1). Directory with NEI csv files.
county: SpatVector/sf. County boundaries.
year: integer(1) Year to use. Currently only 2017 or 2020 is accepted.
...: Placeholders.

Value

a SpatVector object

Note

Base files for county argument can be downloaded directly from U.S. Census Bureau or by using tigris package. This function does not reproject census boundaries. Users should be aware of the coordinate system of census boundary data for other analyses.

Author

Insang Song

Examples

## NOTE: Example is wrapped in `\dontrun{}` as function requires a large
##       amount of data which is not included in the package.
if (FALSE) { # \dontrun{
nei <- process_nei(
  path = "./data",
  county = system.file("gpkg/nc.gpkg", package = "sf"),
  year = 2017
)
} # }