Algorithm 1 Mapper on scRNA-seq data
Input: a pre-processed gene expression matrix G
Output: a graph Grph capturing topological features of G
1. filtering: apply a filter function f on G
2. binning: fragment the range of f into overlapping intervals and separate G into overlapping bins {B1, B2, …, Bn}
3. clustering: apply hierarchical clustering on each bin and get a series of overlapping clusters C
4. graph generation: create a graph Grph to capture the shape of G based on C