power.f: Statistical power for F tests on means in the analysis of...

In rpsychi: Statistics for psychiatric research

Description

This is an internal function. power.f computes statistical power for F tests on means in the analysis of variance.

Usage

power.f(u, n, delta, sig.level = 0.05)

Arguments

u	degree of freedom of the numerator of the F ratio
n	sample size
delta	Cohen's f
sig.level	a numeric contains the significance level (default 0.05)

Value

Return a numeric containing the statistical power.

Author(s)

Yasuyuki Okumura
Department of Social Psychiatry,
National Institute of Mental Health,
National Center of Neurology and Psychiatry
[e-mail]

References

Cohen J (1988). Statistical power analysis for the behavioral sciences (2nd ed). Hillsdale, NJ: Erlbaum.

Examples

##Cohen (1988) ex.8.1
power.f(u = 3, n = 20, delta=.28, sig.level=.05)
power.f(u = 3, n = 20, delta=.28, sig.level=.10)


##Cohen (1988) ex 8.2
power.f(u = 2, n = 200, delta=.23, sig.level=.01)
power.f(u = 2, n = 200, delta=.33, sig.level=.01)

Example output

Loading required package: gtools
[1] 0.5229454
[1] 0.6527047
[1] 0.996625
[1] 0.9999998

rpsychi documentation built on May 1, 2019, 10:10 p.m.