# Taken from http://127.0.0.1:13966/library/psych/html/cohen.d.html# 

# Obtain 95%CI for a given Cohen's d and sample sizes
# to obtain Cohen's d from t statistic use t2d and CI use d.ci

library(psych)
t2d(t=-4.2,n1=10,n2=10)
-4.2 * sqrt(2/10)
d.ci(.62,n1=20,n2=20)