powerCurve function

Estimate power at a range of sample sizes.

This function runs powerSim over a range of sample sizes.

powerCurve(
  fit,
  test = fixed(getDefaultXname(fit)),
  sim = fit,
  along = getDefaultXname(fit),
  within,
  breaks,
  seed,
  fitOpts = list(),
  testOpts = list(),
  simOpts = list(),
  ...
)

Arguments

• fit: a fitted model object (see doFit).

• test: specify the test to perform. By default, the first fixed effect in fit will be tested. (see: tests ).

• sim: an object to simulate from. By default this is the same as fit (see doSim).

• along: the name of an explanatory variable. This variable will have its number of levels varied.

• within: names of grouping variables, separated by "+" or ",". Each combination of groups will be extended to n rows.

• breaks: number of levels of the variable specified by along at each point on the power curve.

• seed: specify a random number generator seed, for reproducible results.

• fitOpts: extra arguments for doFit.

• testOpts: extra arguments for doTest.

• simOpts: extra arguments for doSim.

• ...: any additional arguments are passed on to simrOptions. Common options include:

  • nsim:: the number of simulations to run (default is 1000).
  • alpha:: the significance level for the statistical test (default is 0.05).
  • progress:: use progress bars during calculations (default is TRUE).

Examples

## Not run:

fm <- lmer(y ~ x + (1|g), data=simdata)
pc1 <- powerCurve(fm)
pc2 <- powerCurve(fm, breaks=c(4,6,8,10))
print(pc2)
plot(pc2)
## End(Not run)

See Also

print.powerCurve, summary.powerCurve, confint.powerCurve