Algorithm 1 Divide_Datasets.
Input: Multi-density Dataset D
Output: Dataset summary after dividing the dataset DD
1	X = read(D)  // read data into X
2	disMat = squareform(X)  // Calculate the distance between any two points.
3	for I in disMat
4		i.sort()  // Sort each row of data
5		array.append(i[k])  // The kth nearest neighbor distance of each point is stored in an array.
6	Use plt.plot to draw a distance line chart on the array;
7	Calculate array[i + 1]-array[i] successively from the figure to find the point with obvious height difference, and mark array[i + 1] as the bifurcation point;
8	Use index binding to divide the dataset into two parts left and right of the bifurcation point;
9	return DD