Figure 5.
Clustering outcomes on the density contour map created using multidimensional scaling (MDS) (Torgerson 1952). MDS reduces the number of dimensions of the features derived from SpatialPCA (identified to be the best data transformation method previously). The density is estimated using kernel density estimation (Scott 2015) on the space of the MDS reduced dimensions. The data transformation methods used are SpatialPCA, stLearn, and Stagate, and the clustering methods are as employed in their respective papers (Dong and Zhang 2022; Shang and Zhou 2022; Pham et al. 2023), except the proposed KBC.
