The path measurements include:
The number of connections between path's nodes.
The lengths of the segments determined by a node and its child nodes.
Several angles around the nodes of the path.
For measurement purposes the nodes that comprise a path are labeled and classified.
For each Object with a path defined, isolated subpaths are determined. A subpath is a set of connected nodes, that are not connected with others subpaths. Figure 1 shows a path comprised of connected nodes, and Figure 2 shows a path comprised of two isolated subpaths.
For each subpath the process determines:
A root node – a node of the subpath with one node connected to it.
The branches nodes – the nodes with 3 or more nodes connected to them.
The terminals nodes – the nodes with one node connected to them, which are not the root.
The nodes that do not meet the preceding criteria are intermediate nodes, and they are not taken into account for measurement purposes (in this version of BioVis3D).
Each path is labeled starting with number 1, the sequence will then follow the number of nodes in the path. The root node of each subpath is labeled with the consecutive number as of the last node labeled in the previous subpath processed.
Figure 1: Path comprised of connected nodes – The node labeled 1 is the root node (it has one connection), the node labeled 2 is a branch node (it has 3 connections), and the nodes labeled 3 and 4 are terminals nodes (they have 1 connection).
Figure 2: Path comprised of two subpaths – Each subpath is comprised of connected nodes, being that the subpaths are not connected. The second subpath is labeled starting in number 5, because the preceding subpath finishes in 4. The node labeled 5 is the root node of the second subpath, the node labeled 6 is a branch node, and the nodes labeled 7 and 8 are terminals nodes.
Figure 3: Intermediate nodes of the path – Note that the intermediate nodes (the ones not classified as root, branch or terminal, shown in the figure with colors green and yellow) do determine the trace of the path, but they are not labeled, they are not shown in the 3D View, and they are not taken into account for measurement purposes.
Parent node and child nodes: Each path is subdivided into subpaths, where each subpath is a tree, with a root arbitrary selected. Each node has a parent node (not in the case of the root node), and it could have child nodes. In Figure 3, the branch node labeled 2 has the parent node 1, and the child nodes 3 and 4.
Measuring is done for the nodes classified as root, branch or terminal (intermediate nodes will be considered in future versions of BioVis3D).
The measurements are exported to a tabseparated text file, with extension .TXT that can be imported by a spreadsheet or scientific application, or opened with a text editor. To export paths measurements see Export Sequence.
The following information is measured and exported:
For each node classified as root, branch or
terminal:
 the node label
 the node type
(root, branch, terminal)
 the number of connections

the node diameter
 the node position (in the unit of measure of
the sequence, and in pixels)
Table 1 shows the exported information
opened and formatted with a spreadsheet application.
Table 1: Information about the nodes
For each node classified as branch and
for each correspondent child node:
 the threedimensional Euclidean
distance between the branch node and the child node (note that the length of
the trace between the branch node and the child node is not measured).
 the angle between the parent node of the branch, the branch node and the
child node. The angle is expressed in degrees.
Table 2 shows the
exported information opened and formatted with a spreadsheet
application.
Table 2: Information of the branchchild
For each node classified as branch and
for its correspondent pairs of child nodes:
 the angle between one child
node, the parent node, and a second child node. The child nodes are selected
by pairs, from the lowest label to the highest one as follows: if the branch
node 2 has four children, labeled 3, 4, 5 and 6, the angles measured would be
324, 425, 526. The angle is expressed in degrees.
Table 3
shows the exported information opened and formatted with a spreadsheet
application.
Table 3: Information about the branchchild pairs