function (n = 10) 
{
    alpha = 0.05
    tcrit = qt(1 - alpha/2, n - 1)
    delta = seq(-5, 5, 0.1)
    power = 1 - pt(tcrit, n - 1, delta) + pt(-tcrit, n - 1, delta)
    plot(delta, power, type = "l", col = "blue", xlab = expression(delta == 
        sqrt(n) * (mu - mu[0])/sigma), ylab = expression(beta(delta)), 
        ylim = c(-0.05, 1.05))
    abline(h = seq(0.05, 0.95, 0.05), col = "grey")
    abline(v = seq(-5, 5, 0.5), col = "grey")
    text(0, 1.035, paste("sample size n =", n))
    lines(delta, power, col = "blue")
    abline(h = c(0, 1))
    abline(h = alpha, col = "blue")
    alpha1 = 0.01
    tcrit = qt(1 - alpha1/2, n - 1)
    delta = seq(-5, 5, 0.1)
    power = 1 - pt(tcrit, n - 1, delta) + pt(-tcrit, n - 1, delta)
    lines(delta, power, col = "red")
    abline(h = c(0, 1))
    legend(-2, 0.97, expression(alpha == 0.05, alpha == 0.01), 
        bty = "n", col = c("blue", "red"), lty = c(1, 1))
    abline(h = alpha1, col = "red")
}