  To uncover the genetic basis of complex disease, individuals are often
measured at a large number of genetic variants (usually SNPs) across the
genome. GemTools provides computationally efficient tools for modeling genetic
ancestry based on SNP genotypes. The main algorithm creates an eigenmap based
on genetic similarities, and then clusters subjects based on their map
position. This process is continued iteratively until each cluster is
relatively homogeneous. For genetic association studies, GemTools matches cases
and controls based on genetic similarity.
