Fig. 1
From: Ultrafast clustering of single-cell flow cytometry data using FlowGrid
An illustrative example of the FlowGrid clustering algorithm. In this example, Bin 1, Bin 2, Bin 3 and Bin 6 are core bins as their Denb are larger than MinDenb (5 in this example), their Denc are larger than MinDenc (20 in this example), and their Denb are larger than ρ% (75% in this example) of its directly connected bins. \(Dist(C_{1}, C_{2}) =\sqrt {1^{2}+1^{2}} =\sqrt {2} \leq \sqrt {\epsilon }\) (ε=2 in this example), so Bin 1 and Bin 2 are directly connected. \(Dist(C_{2}, C_{4}) =\sqrt {1^{2}+1^{2}} = \sqrt {2} \leq \sqrt {\epsilon }\), so Bin 2 and Bin 4 are directly connected. Therefore, Bin 1, Bin 2 and Bin 4 are mutually connected, and they are assigned into the same cluster. Bin 5 is not a core bin but is a border bin, as it is directly connected to Bin 6, which is a core bin. Bin 3 is a outlier bin, as it is not a core bin nor a border bin. In practice, MinDenb is set to be 3, MinDenc is set to 40 and ρ is set to be 85