Expected power for an association study from the derived equations and observed averaged power from simulation.

h2: variance explained by the locus.a: in case-control samples, 50% of the sample are cases, P = 0.5.Exp: Expected power based on NCP derived from equation (1)∼(4).Obs: Averaged power over 10000 replicates of simulation.SE: Empirical standard error over 10000 replicates.h₂：该位点解释的方差。a：在病例-对照样本中，50%的样本为病例，P=0.5。Exp：基于式(1)~(4)推导所得非中心参数（non-centrality parameter, NCP）计算的期望检验效能。Obs：10000次模拟重复实验的平均检验效能。SE：10000次重复实验的经验标准误。