plot {sse} | R Documentation |
A sensitivity plot (called power plot) for the sample size
calculation. Using a contour for a given power, it shows how sample
size changes if theta
is varied.
plot(x, y, ...)
x |
The object of class power used for plotting |
y |
Not used |
... |
additional arguments implemented:
|
Generates a contour plot with theta on the x-axis and n on the y-axis and the contours for the estimated power (indicated with the argument at).
A plot is generated but nothing is returned.
inspect
for drawing an inspection plot and
levelplot
for further arguments that can be passed to
plot.
## 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 the power plot with 3 contour lines plot(pow, xlab = "Standard Deviation", ylab = "Total Sample Size", at = c(0.85, 0.9, 0.95)) ## without example the contour line at the first element of at is bold plot(pow, example = FALSE)