select_waypoints: Add or create waypoints to a trajectory

Description

Waypoints are points along the trajectory, which do not necessarily correspond to cells. They are selected in such a way that all parts of the trajectory are covered

Usage

select_waypoints(
  trajectory,
  n_waypoints = 200,
  trafo = sqrt,
  resolution = sum(trafo(trajectory$milestone_network$length))/n_waypoints,
  recompute = FALSE
)
add_waypoints(
  trajectory,
  n_waypoints = 200,
  trafo = sqrt,
  resolution = sum(trafo(trajectory$milestone_network$length))/n_waypoints,
  recompute = FALSE
)
is_wrapper_with_waypoints(trajectory)

Value

add_waypoints returns the trajectory with waypoints added, which is a list containing:

milestone_percentages and progressions: The milestone percentages and progressions of each waypoint, in the same format as the cell equivalents (see add_trajectory()) but with a waypoint_id column instead of a cell_id column
geodesic_distances: a matrix with the geodesic distance of each waypoint (rows) to every cell (columns)
waypoint_network: a dataframe containing the network between consecutive waypoints, it contains information on the connected waypoints (from and to) and the edge on which they reside (from_milestone_id and to_milestone_id)
waypoints: the waypoint identifiers

**select_waypoints returns the list as mentioned in add_waypoints

Arguments

trajectory: The trajectory as created by infer_trajectory() or add_trajectory()
n_waypoints: The number of waypoints
trafo: Transformation function of the edge lengths
resolution: The resolution of the waypoints, measured in the same units as the lengths of the milestone network edges, will be automatically computed using n_waypoints
recompute: Force recompute