R: Interactive power calculations for a two-sample t-test
rp.power
R Documentation
Interactive power calculations for a two-sample t-test
Description
This function creates a panel which allows the sample size, population means and common standard deviation to be set. The correponding power curve for a two-sample t-test is displayed in the graphics window.
a logical value determining whether an interactive panel is created.
panel.plot
a logical value determining whether the plot is placed inside the panel.
populations.showing
a logical value determining whether the populations are initially showing.
ngrid
a vector which determines the grid a sample sizes used.
mu1,mu2
the initial values of the means of the two populations.
sigma
the initial value of the common standard deviation of the two populations.
n
the initial value of the sample size.
xgrid
the grid of values over which the populations are plotted.
popdens.lim
the upper limit on the population density scale.
hscale, vscale
scaling parameters for the size of the plot.
Details
The population parameters and sample size are controlled by doublebuttons. The sample size refer to the total sample size, assuming two groups of equal size. A checkbox allows plots of the population distributions also to be diplayed.
Value
Nothing is returned.
References
rpanel: Simple interactive controls for R functions using the tcltk package.
Journal of Statistical Software, 17, issue 9.