.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
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).
