tmpar <- par( mar=c(4.1,4.1,0,0) )

groups <- 2:20
alpha <- .05

# equivalent comparisons between B and S
tmpa <- log( alpha / ( 2 * ( 1 - pnorm( sqrt( qchisq( .95, groups - 1 ))))))
plot(groups, tmpa, type="l", yaxt="n",
	xlab="number of groups", ylab="comparisons" )
axis( 1, c(2,13) )
axis( 2, log( c(1,10,78,1000,10000,100000,1000000) ),
	c("1","10","78","1000","10^4","10^5","10^6"), adj=1 )
axis( 2, log(100), F )
lines( c(13,13), c(0,tmpa[12]), lty=2 )
lines( c(2,13), rep(log(78),2), lty=2 )

rm( groups, alpha, tmpa )
par( tmpar )