Figure 4

Examples of contour trees extracted from discrete samples on functions$R^2\to R$and$R^3\to R$. (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].