Fig. 2

Illustration of the differences introduced by graph construction methods. a Synthetic dataset consisting of four groups of randomly sampled points: three groups are sampled from a circle and one group from its centre. b The minimum spanning tree (MST) of the dataset based on Euclidean distances. We also present the graphs constructed with MST-based methods: c PMST and d RMST, as well as neighbourhood methods: e kNN and f CkNN. RMST, kNN and CkNN are shown for different parameters that vary the sparsity of the resulting graphs