This is a part of my Capstone Research. 

To get property of a branch, it is easy to consider its volume and tortuosity .

I assume the volume of a branch is the sum of all the radius of nodes in a branch, and the tortuosity is defined as the linked distance of each nodes to the proportion of distance from first to last node.

The second is a 90 degree rotation of the first one, branches marked as (id:volume,tortuosity) From the number, we find each branch can be uniquely identified according to the size of properties of each branch.