\begin{Schunk}
\begin{Sinput}
 par.orig <- par(no.readonly=TRUE)
 par(mar = c(4.1, 4.1, 2.1, 2.1))
 cumlogis <- plogis(x, location = 0, scale = 1, log = FALSE)
 plot(x, cumlogis, type="l", ylim=c(0,1), xlab=expression(tau),
        ylab="Cumulative Probability", main="") 
 abline(v=xcut, lty = 4, col = "gray80")
 par(par.orig)
\end{Sinput}
\end{Schunk}
