Root the trajectory

Roots the trajectory by changing the directionality of all edges given a root cell

add_root(trajectory, root_cell_id = trajectory$root_cell_id,
  root_milestone_id = trajectory$root_milestone_id)

Arguments

trajectory	the trajectory object
root_cell_id	The root cell id, not required if root_milestone_id is given
root_milestone_id	The root milestone id, not required if root_cell_id is given