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Process U.S. EPA AQS daily CSV data

Source: R/process.R
process_aqs.Rd

The process_aqs() function cleans and imports raw air quality monitoring sites from pre-generated daily CSV files, returning a single SpatVector or sf object. date is used to filter the raw data read from csv files. Filtered rows are then processed according to mode argument. Some sites report multiple measurements per day with and without exceptional events the internal procedure of this function keeps "Included" if there are multiple event types per site-time.

Usage

process_aqs(
  path = NULL,
  date = c("2018-01-01", "2022-12-31"),
  mode = c("date-location", "available-data", "location"),
  data_field = "Arithmetic.Mean",
  return_format = c("terra", "sf", "data.table"),
  extent = NULL,
  ...
)

Arguments

path

character(1). Directory path to daily measurement data.

date

character(1 or 2). Date (1) or start and end dates (2). Should be in "YYYY-MM-DD" format and sorted.

mode

character(1). One of

  • "date-location" (all dates * all locations)

  • "available-data" (date-location pairs with available data)

  • "location" (unique locations).

data_field

character(1). Data field to extract.

return_format

character(1). "terra" or "sf" or "data.table".

extent

numeric(4). Spatial extent of the resulting object. The order should be c(xmin, xmax, ymin, ymax). The coordinate system should be WGS84 (EPSG:4326).

...

Placeholders.

Value

a SpatVector, sf, or data.table object depending on the return_format

Note

Choose date and mode values with caution. The function may return a massive data.table depending on the time range, resulting in a long processing time or even a crash if data is too large for your computing environment to process.

See also

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{
aqs <- process_aqs(
  path = "./data/aqs_daily_example.csv",
  date = c("2022-12-01", "2023-01-31"),
  mode = "full",
  return_format = "terra"
)
} # }