# Power function of a standard t-test, by Sean van der Merwe,UFS library(rgl) library(manipulate) mu <- seq(-5,5,l=101) mumat <- matrix(mu,101,101) sigma <- 2^seq(-2,2,l=101) sigmamat <- matrix(sigma,101,101,byrow=T) manipulate({ plot(c(0,1),c(0,1),type='n',main=expression(paste(H[0],": ",mu==0))) p <- 1-pf(qf(0.95,1,n-1),1,n-1,(n*(mumat^2)/(sigmamat^2))) persp3d(mumat,sigmamat,p,col=thecol) },n=slider(5,50,label='Sample Size: '),thecol=picker('cyan','blue','red','purple','green','pink',initial='cyan',label='Colour: '))