x <- rnorm(15)

y <- x + rnorm(15)

predict(lm(y ~ x))

new <- data.frame(x = seq(-3, 3, 0.5))

predict(lm(y ~ x), new, se.fit = TRUE)

pred.w.plim <- predict(lm(y ~ x), new, interval = "prediction")#拟合值置信区间

matplot(new$x, pred.w.plim,lty = c(1,2,2), type = "l", ylab = "predicted y")

pred.w.clim <- predict(lm(y ~ x), new, interval = "confidence")#观测值置信区间

matplot(new$x, pred.w.clim, lty = c(1,2,2), type = "l", ylab = "predicted y")