From: Robust methods for population stratification in genome wide association studies
 |  | Case | Control |
---|---|---|---|
 |  | proportion | proportion |
S1 | (moderate) | (0.6,0.4)a | (0.4,0.6)b |
S2 | (more extreme) | (0.5,0.5) | (0,1) |
S3 | (moderate) | (0.45,0.35,0.20) | (0.35,0.20,0.45) |
S4 | (more extreme) | (0.33,0.67,0) | (0,0.33,0.67) |