The Minimum Spanning Tree view
MSTs can be seen in MLST Schemes or MLST Comparisons, by selecting the Minimum Spanning Tree view (
) in the bottom-left of the view area (see figure 10.6).
Figure 10.6: The Minimum Spanning Tree view.
An initial layout is calculated for a minimum spanning tree during its creation, but it is possible to make changes to the layout.
If a change is made, the layout will be updated using a force-directed layout: fictional forces are assigned to the tree nodes so that non-connected nodes will repel each other, while connected nodes will be held together with a spring force.
It is important to note that branch lengths in a force-directed layout may not be proportional to their ideal distance due to the repulsive force - in fact, the distance can be very different near heavy clusters.