Checking and converting coordinates
This is used as a checking mechanism for other functions to ensure data is given in the appropriate format, and if it is not, converting to the appropriate format where possible.
A vector, matrix or dataframe to be checked
ensure3d checks to ensure that the given data are one or more sets of 3D Cartesian coordinates, and converts them to numeric vectors if they are not already. If latitudes and longitudes are given as input into ensure3d, they will be converted to 3D Cartesian coordinates, on the unit sphere. ensurelonlat checks to ensure that the given data are one or more pairs of longitude and latitude and converts the data to a pair of lists if they are not already. Vectors and single rows/columns of matrices can be used as input for both functions; multiple rows/colums of matrices and pairs of lists can also be used as input for ensurelonlat.
ensure3d A numeric vector or matrix ensurelonlat
List of Longitudes
Adrian Baddeley and Tom Lawrence