eta omega epsilon

[Lakens]

Calculate less biased effect sizes:
result.anova
SSb <- result.anova[1,2]
SSt <- result.anova[1,2] + pilot.anova[2,2]
MSw <- result.anova[2,3]
eta2 <- SSb/SSt
epsilon2 <- max((SSb - (cK-1)*MSw)/SSt,0) # the 'max' makes sure it's non-negative
omega2 <- max((SSb - (cK-1)*MSw)/(SSt+MSw),0)