\begin{Schunk}
\begin{Sinput}
 tb1hat <- vector(nsims, mode="numeric")
 for (i in 1:nsims){ tb1hat[i] <- (coefficients(res[[i]])[2,1]-b1)/coefficients(res[[i]])[2,2]}
 hist(tb1hat, breaks=20, probability=T, main="", xlab=expression( hat(t) == (hat(b)[1]-b[1])/s.e.(hat(b)[1])))
 lines(density(tb1hat), lty=4)
 rtb1hat <- range(tb1hat)
 xseq <- seq(from=rtb1hat[1],to=rtb1hat[2],length.out=200)
 lines(xseq, dt(xseq, df=98))
 legend("topleft", legend=c("Theoretical", "Simulated kde"), lty=c(1,4))
\end{Sinput}
\end{Schunk}
