Check and convert lat/lon to decimal degrees

Check that latitude and longitude are in decimal degrees and the variable sign is correct. Correct lat/lon if required.

Usage

degree(
  dat,
  project,
  lat = NULL,
  lon = NULL,
  latsign = FALSE,
  lonsign = FALSE,
  replace = TRUE
)

Arguments

dat: Dataset containing latitude and longitude data.
project: Project name.
lat: Variable(s) containing latitude data. If NULL the function will attempt to search for all latitude variables by name (e.g. by matching "lat" or "LAT").
lon: Variable(s) containing longitude data. If NULL the function will attempt to search for all longitude variables by name (e.g. by matching "lon" or "LON").
latsign: How should the sign value of lat be changed? Choices are NULL for no change, "neg" to convert all positive values to negative, "pos" to convert all negative values to positive, and "all" to change all values.
lonsign: How should the sign value of lon be changed? Choices are NULL for no change, "neg" to convert all positive values to negative, "pos" to convert all negative values to positive, and "all" to change all values.
replace: Logical, should lat and lon in dat be converted to decimal degrees? Defaults to TRUE. Set to FALSE if checking for compliance.

Value

Returns the primary dataset with the latitudes and longitudes converted to decimal degrees if replace = TRUE or if Changing the sign. Otherwise, a message indicating whether selected longitude and latitude variables are in the correct format.

Details

First checks whether any variables containing 'lat' or 'lon' in their names are numeric. Returns a message on results. To convert a variable to decimal degrees, identify the lat or lon variable(s) and set replace = TRUE. To change the sign, set latsign (for lat) or lonsign (for lon = TRUE. FishSET requires that latitude and longitude be in decimal degrees.

Examples

if (FALSE) {
# check format
degree(pollockMainDataTable, 'pollock', lat = 'LatLon_START_LAT',
       lon = 'LatLon_START_LON')

# change signs and convert to decimal degrees
pollockMainDataTable <- degree(pollockMainDataTable, 'pollock', 
                               lat = 'LatLon_START_LAT', 
                               lon = 'LatLon_START_LON', latsign = FALSE, 
                               lonsign = FALSE, replace = TRUE)
}