Etna_boundary           Dataset: bounding polygon representing a study
                        area on Mount Etna (Sicily, Italy)
Etna_end_location       Dataset: locations on Mount Etna (Sicily,
                        Italy)
Etna_start_location     Dataset: location on Mount Etna (Sicily, Italy)
destin.loc              Dataset: locations on the volcano Maunga Whau
                        (Auckland, New Zealand)
movecorr                R function for calculating least-cost corridor
                        between two point locations
movecost                R function for calculating accumulated
                        anisotropic cost of movement across the terrain
                        and least-cost paths from an origin
volc.loc                Dataset: location on the volcano Maunga Whau
                        (Auckland, New Zealand)
