Free Access
Fig. 1
Illustration of the essential trees needed by root box 4. The different levels of the tree structure which need to be copied depend on the distance to the nearest boundary of root box 4 and the opening angle θ. See text for details.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.