.calculateCrossingPercentageCmplx
                        Calculates percentage of trajectory segment
                        within circle
calculateIntervalResidenceTime
                        Calculates residence time within user-specified
                        breaks
drawCircle              Draws a circle
getRecursions           Calculates recursion information from the
                        trajectory
getRecursions3D         Calculates recursion information from the 3D
                        trajectory
getRecursions3DAtLocations
                        Calculates recursion information from the 3D
                        trajectory for specific locations
getRecursionsAtLocations
                        Calculates recursion information from the
                        trajectory for specific locations
getRecursionsInPolygon.Move
                        Calculates recursion information from the
                        trajectory inside a polygon
martin                  Sample trajectory (martin).
plot.recurse            Calculates recursion information from the
                        trajectory
recurse                 Computes revisitation metrics for trajectory
                        data
track                   Sample trajectory (track).
wren                    Sample trajectory (wren).
