get_elevation() takes a dataframe that includes GPS coordinates (in decimal degrees) and returns a dataframe with two new columns added to it, minimumElevationInMeters and maximumElevationInMeters. The function requires that the data supplied are numeric and that missing values are specified with NA.
get_elevation(
df,
decimal_lat,
decimal_long,
spatial_ref = c(4326, 102100),
force = FALSE
)a data frame containing GPS decimal coordinates for individual points with latitude and longitude in separate columns.
String. The name of the column containing longitudes
String. The name of the column containing latitudes
Categorical. Defaults to 4326. Can also be set to 102100.
Logical. Defaults to FALSE. Returns verbose comments, interactions, and information. Set to TRUE to remove all interactive components and reduce/remove all comments and informative print statements.
a data frame with two new columns, minimumElevationInMeters and maximumElevationInMeters
get_elevation() uses the USGS API for The National Map to identify the elevevation for a given set of GPS coordinates. To reduce API queries (and time to completion), the function will only search for unique GPS coordinates in your dataframe. This could take some time. If you have lots of GPS coordinates, you can also perform a manual bulk upload (maximum = 500 points).
Note that both new columns (minimumElevationInMeters and maximumElevationInMeters) contain the same elevation; this is expected behavior as a single GPS coordinate should have the same maximum and minimum elevations. The column names are generated in accordance with the simple Darwin Core Standards.
Points outside of the US may return NA values as they are not part of The National Map.
if (FALSE) { # \dontrun{
new_dataframe <- get_elevation(df,
"decimalLatitude",
"decimalLongitude",
spatial_ref="4326")
new_dataframe <- get_elevation(df,
"decimalLatitude",
"decimalLongitude",
spatial_ref="102100",
force=TRUE)
} # }