#Power analysis t-test
## Computing the required n
power.t.test(delta=100, sd=50, power=0.8, sig.level=0.05, strict=FALSE)

## Computing the power
power.t.test(delta=100, sd=50, n=4, sig.level=0.05, strict=FALSE)

#Power analysis Two-way ANOVA
install.packages("pwr2")
library(pwr2)
ss.2way(a=2, b=2, alpha=0.05, beta=0.2, f.A=0.36, f.B=0.64, B=100)

#a and b are the number of factors in each group, B is bootstrap number
# F.A and F.B are the Partial eta squared (0.64 large, 0.25-0.36 moderate, and 0.09 minor effect)