Moving nodes. To move a node simply drag and drop. The location and coverage circle will move along with the mouse. After you have dropped the node into the new location the complex will be recalculated and rendered.
Deleting nodes. To delete nodes simply click to highlight each node you wish to remove and press the "Delete" key. To cancel press the "Esc" key.
Adding nodes. To add nodes click the "Add nodes" button. The cursor will change to a crosshair. Click the location for each node you would like to add. When you are done press the "Esc" key.
Zooming and panning. To enter zoom mode, press the "Z" key. While in zoom mode you may pan the plot view by left-clicking, holding the mouse button down and moving the mouse in the plot area. To zoom in or out use the mouse wheel.
Nodes correspond to sensor locations. Hovering over a node will highlight the coverage radius for that individual sensor.
Edges correspond to the lines connecting each node. An edge only exists if the coverage radii overlap for two nodes. Hovering over an edge will highlight the edge and its corresponding nodes.
Faces correspond to filled triangles indicating where three points are mutually connected. Hovering over a face
will highlight the face along with the corresponding three points and edges that form the triangle. The presence of a face
depends on which complex type you select:
Čech pertains to a simplicial complex constructed such that where the coverage for each of the three nodes overlaps,
we can guarantee "good" coverage and represent this geometric area as a face or 2-simplex in topological space. (
Reference)
Vietoris-Rips is another, less computationally expensive way of calculating coverage. In this simplicial complex, faces
are generated when 3 points are all pairwise within range of each other with no requirement that all three nodes simultaneously overlap.
The advantage of this over the Čech complex is that it is computationally much less expensive. The disadvantage lies in the fact that
there is the possibility of small coverage gaps within each face where the coverage radii do not all intersect the circumcenter of the resulting triangle
in geometric space. (Reference)