transformZrtoHgapprox {reproducer}

transformZrtoHgapprox

Description

This function provides an approximate transformation from Zr to Hedges g when the number of observations in the treatment and control group are unknown. It is also used to allow the forest plots to display Hedge's g when they are based on r. It is necessary because the transformation function in the forest plot function does not allow any parameters other than effect size used. The function assumes that Nc=Nt and gives the same results as transformZrtoHg when Nc=Nt.

Usage

transformZrtoHgapprox(Zr)

Arguments

Zr

A vector of normalised point bi-serial values

Value

approx. value of Hedges' g

Author(s)

Barbara Kitchenham and Lech Madeyski

Examples

transformZrtoHgapprox(c(0.4, 0.2))
# [1] 0.8215047 0.4026720