inspect {sse}

Inspection Plot

Description

Creating a plot that allows to inspect the sample size calculation.

Usage

inspect(object)

Arguments

object

An object of class power.

Details

The plot shows for every evaluated theta the sample size and the power on a transformed scale. The method used for sample size estimation 'step' or 'lm' is indicated. If the method 'lm' is used a red regression line is shown for the range that was used for estimation.

Value

A plot is generated but nothing is returned.

Examples

## defining the range of n and theta to be evaluated
psi <- powPar(theta = seq(from = 0.5, to = 1.5, by = 0.1),
              n = seq(from = 20, to = 60, by = 2),
              muA = 0,
              muB = 1)

## defining a power-function               
powFun <- function(psi){
  power.t.test(n = n(psi)/2,
               delta = pp(psi, "muA") - pp(psi, "muB"),
               sd = theta(psi)
               )$power
}

## evaluating the power-function for all combinations of n and theta
calc <- powCalc(psi, powFun)

## adding example at theta of 1 and power of 0.9
pow <- powEx(calc, theta = 1, power = 0.9)

## drawing an inspection plot
inspect(pow)