power.anova.test
Power Calculations for Balanced OneWay Analysis of Variance Tests
Compute power of test or determine parameters to obtain target power.
 Keywords
 htest
Usage
power.anova.test(groups = NULL, n = NULL, between.var = NULL, within.var = NULL, sig.level = 0.05, power = NULL)
Arguments
 groups
 Number of groups
 n
 Number of observations (per group)
 between.var
 Between group variance
 within.var
 Within group variance
 sig.level
 Significance level (Type I error probability)
 power
 Power of test (1 minus Type II error probability)
Details
Exactly one of the parameters groups
, n
, between.var
,
power
, within.var
, and sig.level
must be passed as NULL,
and that parameter is determined from the others. Notice that
sig.level
has nonNULL default so NULL must be explicitly
passed if you want it computed.
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.
See Also
Examples
library(stats)
power.anova.test(groups = 4, n = 5, between.var = 1, within.var = 3)
# Power = 0.3535594
power.anova.test(groups = 4, between.var = 1, within.var = 3,
power = .80)
# n = 11.92613
## Assume we have prior knowledge of the group means:
groupmeans < c(120, 130, 140, 150)
power.anova.test(groups = length(groupmeans),
between.var = var(groupmeans),
within.var = 500, power = .90) # n = 15.18834
Community examples
Looks like there are no examples yet.