A mathematically defined repeat (MDR) is a experimental feature that is determined by querying overlapping oligomers of length k against a database of shotgun sequence data and identifying regions in the query sequence that exceed a statistically determined threshold of repetitiveness.
Comment:
Mathematically defined repeat regions are determined without regard to the biological origin of the repetitive region. The repeat units of a MDR are the overlapping oligomers of size k that were used to for the query. Tools that can annotate mathematically defined repeats include Tallymer (Kurtz et al 2008, BMC Genomics: 517) and RePS (Wang et al, Genome Res 12(5): 824-831.).