twomeans: Two-sample t-test power calculation

In vikjam/pwrcalc: An R power package familiar to Stata users

Description

Two-sample t-test power calculation

Usage

twomeans(m1 = NULL, m2 = NULL, n1 = NULL, n2 = NULL,
  nratio = NULL, sd = NULL, sd1 = NULL, sd2 = NULL,
  sig.level = 0.05, power = 0.8)

Arguments

m1	Mean of a group 1 (e.g., the control-group)
m2	Mean of a group 2 (e.g., the experimental-group)
n1	Number of obs. in group 1 (e.g., the control-group)
n2	Number of obs. in group 2 (e.g., the control-group)
nratio	Ratio of sample sizes, group 2 to group 1; default is nratio = 1, meaning equal group sizes
sd	Standard deviation of each group, i.e., sd = sd1 = sd2
sd1	Standard deviation of a group 1 (e.g., the control group)
sd2	Standard deviation of a group 2 (e.g., the experimental group)
sig.level	significance level; default is sig.level = 0.05
power	one minus the probability of type II error; default is power = 0.8

Value

Returns an object with all the study parameters

Examples

twomeans(m1 = 12, m2 = 16, sd = 5)

vikjam/pwrcalc documentation built on May 5, 2019, 5:55 p.m.