Fig. 2

The decision map which includes 34 switch point. x axis: \(\rho\): This symbol represents the local density of switch nodes, which means the size of the number of data points in a certain area. y axis: \(\delta\): This symbol represents the relative distance of switch nodes, but the calculation of this value can be divided into two cases. Case 1: for the switch node with the highest density, because of there is no switch node with higher density, its relative distance is defined as the maximum distance between the switch node and all other switch nodes. Case 2: for other switch nodes, the relative distance is defined as the shortest distance between the switch node and other switch nodes with higher local density