Utility function to check if a coordinates is valid

Utility function to check if a coordinates is valid

validateCoords(lng, lat, funcName, warn = TRUE, mode = c("point",
  "polygon"))

Arguments

lng	vector with longitude values
lat	vector with latitude values
funcName	Name of calling function
warn	A boolean. Whether to generate a warning message if there are rows with missing/invalid data
mode	if "point" then warn about any NA lng/lat values; if "polygon" then NA values are expected to be used as polygon delimiters