R: Power calculations for the general linear model

pwr.f2.test {pwr} | R Documentation

## Power calculations for the general linear model

### Description

Compute power of test or determine parameters to obtain target power (same as power.anova.test).

### Usage

    pwr.f2.test(u = NULL, v = NULL, f2 = NULL, sig.level = 0.05, power = NULL)

### Arguments

`u` | degrees of freedom for numerator
`v` | degrees of freedomfor denominator
`f2` | effect size
`sig.level` | Significance level (Type I error probability)
`power` | Power of test (1 minus Type II error probability)

### Details

Exactly one of the parameters 'u','v','f2','power' and 'sig.level' must be passed as NULL, and that parameter is determined from the others. Notice that the last one has non-NULL default so NULL must be explicitly passed if you want to compute it.

### Value

Object of class '"power.htest"', a list of the arguments (including the computed one) augmented with 'method' and 'note' elements.

### Note

'uniroot' is used to solve power equation for unknowns, so you may see errors from it, notably about inability to bracket the root when invalid arguments are given.

### Author(s)

Stephane Champely <champely@univ-lyon1.fr> but this is a mere copy of Peter Dalgaard work (power.t.test)

### References

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

### Examples

    ## Exercise 9.1 P. 424 from Cohen (1988)
    pwr.f2.test(u=5,v=89,f2=0.1/(1-0.1),sig.level=0.05)

[Package pwr version 1.2-2 Index]