# January 20, 2009

	# Asymptotics of regression for predicting class 0 vs 1


eg.0120 = function( f1=2/3, del=seq(0,15,len=201), add=F ) {

    den = 1+del^2*(1-f1)
    b0 = f1 / den; b1 = del*(1-f1)/den
    if(!add) { plot(del,b0,ylim=range(b0,b1,1),type="l",ylab="") } else
        { lines(del,b0) }
    lines(del,b1,col=2,lwd=2)
    legend( .6*max(del), .8*max(b0,b1,1), c("Intercept","Slope"),
	    col=c(1,2),lwd=c(1,2))
    text(.7*max(del),.6*max(b0,b1,1),paste("f 1 = ",round(f1,3)))
}

par(mfrow=c(2,2), mar=c(3,3,.1,.1))
eg.0120(.5)
eg.0120(2/3)
eg.0120(.85)
eg.0120(.999)