Gabriel Graph Condensing (GG)

In GG (Gabriel Graph) two points, xi and xj, are neighbours if and only if there is no other point from set laying in a hypersphere between xi, xj centered at their middle point and whose diameter is equal to the distance between them.

Algorithmically, the GG condensing scheme can be written as follows:

• Construct the proximity graph corresponding to the original Training Set, say X.
• Visit each node of the proximity graph and mark the visited node if all its graph neighbours are not from the same class as the node visited.
• Discard all prototypes in X corresponding to nodes in the proximity graph that are not marked.

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How to use this applet?

1. The top panel is Modes panel, the right panel is Controls panel and the central panel is Drawing panel.
2. To select the number of classes (label No classes) in the controls panel for the training set.
3. To do click over any radiobutton that identify a class (labels 1, 2, ..., 12) in the controls panel.
4. To do click over the drawing panel to insert prototypes in the training set (of the class selected in the step 4). These prototypes will have 2 characteristics whose values will remain defined for the axes x and y.
5. To select el radiobutton with label "2. Condensing" in the modes panel to changing to the condening mode. Then you can see the resultant set of the condensing.
6. The radiobutton with label Inspection in the controls panel allows to know the coordinates of the next prototype (o sample) to the cursor mouse.
7. The radiobutton with label Remove (only in design mode) in the controls panel allows delete the next prototype (o sample) to the cursor mouse.
8. The button Clear (only in design mode) in the controls panel allows delete all the training set.