These are simulated data, consisting of 300 F2 individuals
typed at 100 markers on five chromosomes. There are no real phenotypes,
just a set of individual identifiers. The data were simulated for the
purpose of illustrating the process of constructing a genetic map. The
markers are all assigned to a single chromosome and in a random order,
and there are a number of problematic markers and individuals.
Broman, K. W. (2010) Genetic map construction with R/qtl. Technical
report #214, Department of Biostatistics and Medical Informatics,
University of Wisconsin--Madison