Figure 4
From: Visual data mining based on differential topology: a survey

Examples of contour trees extracted from discrete samples on functionsand. (a) A digital elevation model around Hakone area, which contains a crater lake (Lake Ashi) surrounded by mountains [17]. (b) Voxel samples at a 3D grid in a volume data, which is obtained through a simulation of the probability distribution of a nucleon in the atomic nucleus 16O[18].