SWBLOCK: Stata module to perform parsimonious model selection in haplotype analysis

This command systematically fits a series of hapipf log-linear models that models the LD structure within a set of loci. The log-linear model is fitted using iterative proportional fitting which is available using ssc and is called ipf (version 1.36 or later). Additionally, the user will also have to install hapipf (version 1.44 or later). This algorithm can handle very large contingency tables and converges to maximum likelihood estimates even when the likelihood is badly behaved.