Figure 1

The pipeline diagram of ARG-walker algorithm. ARG-walker consists of two stages. In Stage 1, from an input sample of haplotypes, the IRiS program is used to reconstruct the ancestral recombination graph (ARG), and the nodes are classified into three types as illustrated with different shapes and colours. In Stage 2, information flows indicating signals of recombination are first gathered to the root nodes through backward random walk, then propagated downwards through forward random walk and in the end gathered by the leaf nodes. The red arrows in Step (iii) and Step (iv) illustrate the start of the random walks.