Invalid coordinates — TADA_FlagCoordinates • EPATADA

This function identifies and flags invalid coordinate data. When clean_outsideUSA = "no" and clean_imprecise = FALSE, a column will be appended titled "TADA.InvalidCoordinates.Flag" with the following flags: 1) If the latitude is less than zero, the row will be flagged with "LAT_OutsideUSA" (with the exception of American Samoa, Northern Mariana Islands, and Guam), 2) If the longitude is greater than zero AND less than 145, the row will be flagged as "LONG_OutsideUSA" (with the exception of American Samoa, Northern Mariana Islands, and Guam), and 3) Finally, precision can be measured by the number of decimal places in the latitude and longitude provided. If either the latitude or longitude does not have at least three numbers to the right of the decimal point, the row will be flagged as "Imprecise". Occasionally latitude and longitude measurements are flagged as outside of the United States because the data was entered as negative when it should be positive or vice versa. This function offers the option of clean_outsideUSA = "change sign" to fix this issue. However, data owners should fix the raw data through WQX. For assistance with changing raw data, email the WQX help desk: WQX@epa.gov

Usage

TADA_FlagCoordinates(
  .data,
  clean_outsideUSA = c("no", "remove", "change sign"),
  clean_imprecise = FALSE,
  flaggedonly = FALSE
)

Arguments

.data: TADA dataframe
clean_outsideUSA: Character argument with options "no", "remove", and "change sign"; flags coordinates as outside the USA when clean_outsideUSA = "no"; removes data with coordinates outside of the United States when clean_outsideUSA = "remove"; changes sign of lat/long coordinates flagged as outside the USA when clean_outside = "change sign"; Default is clean_outsideUSA = "no".
clean_imprecise: Boolean argument; removes imprecise data when clean_imprecise = TRUE. Default is clean_imprecise = FALSE.
flaggedonly: Boolean argument; Return only flagged data when flaggedonly = TRUE; default is flaggedonly = FALSE.

Value

Returns input TADA dataset with the added "TADA.InvalidCoordinates.Flag" column. When clean_outsideUSA is "no", "change sign", or clean_imprecise argument is FALSE, a column flagging rows with the respective QA check is appended to the input dataframe. When clean_outsideUSA is "remove" or clean_imprecise is TRUE, "invalid" or "imprecise" data is removed, respectively. When flaggedonly is TRUE, the dataframe will be filtered to show only the data flagged as invalid, imprecise, or out of the United States. Defaults are clean_outsideUSA = "no", clean_imprecise = FALSE, and flaggedonly = FALSE.

Examples

# Load example dataset:
data(Data_Nutrients_UT)

# Flag, but do not remove, data with invalid coordinates in new column
# titled "TADA.InvalidCoordinates.Flag":
# Return ALL data:
InvalidCoord_flags <- TADA_FlagCoordinates(Data_Nutrients_UT)

# Flag, but do not remove, data with invalid coordinates in new column
# titled "TADA.InvalidCoordinates.Flag"
# Return ONLY the flagged data:
InvalidCoord_flags_flaggedonly <- TADA_FlagCoordinates(Data_Nutrients_UT, flaggedonly = TRUE)

# Remove data with coordinates outside the USA, but keep flagged data with
# imprecise coordinates:
OutsideUSACoord_removed <- TADA_FlagCoordinates(Data_Nutrients_UT, clean_outsideUSA = "remove")

# Change the sign of coordinates flagged as outside the USA and keep all
# flagged data:
OutsideUSACoord_changed <- TADA_FlagCoordinates(Data_Nutrients_UT, clean_outsideUSA = "change sign")
#> [1] "When clean_outsideUSA == change sign, the sign for any lat/long coordinates flagged as outside of USA are switched. This is a temporary solution. Data owners should fix the raw data to address invalid coordinates through WQX. For assistance fixing data errors you see in the WQP, email the WQX helpdesk (WQX@epa.gov)."

# Remove data with imprecise coordinates, but keep flagged data with coordinates outside the USA;
# imprecise data may have less than 3 significant figures to the right
# of the decimal point:
ImpreciseCoord_removed <- TADA_FlagCoordinates(Data_Nutrients_UT, clean_imprecise = TRUE)
#> [1] "All invalid coordinates were removed. Returning input dataframe with TADA.InvalidCoordinates.Flag column for tracking."

# Remove data with imprecise coordinates or coordinates outside the USA from the dataframe:
InvalidCoord_removed <- TADA_FlagCoordinates(Data_Nutrients_UT, clean_outsideUSA = "remove", clean_imprecise = TRUE)
#> [1] "All invalid coordinates were removed. Returning input dataframe with TADA.InvalidCoordinates.Flag column for tracking."