## ---------------- ggplot2 Examples -------------------------

library(ggplot2)

dataMatrix<-read.csv("Ships.csv")
attach(dataMatrix)

# Example1:
qplot(wt, mpg, data=mtcars, colour=factor(cyl))

# Example 2:
model <- lm(mpg ~ wt + factor(cyl), data=mtcars)
grid <- with(mtcars, expand.grid(
  wt = seq(min(wt), max(wt), length = 20),
  cyl = levels(factor(cyl))
))
grid$mpg <- stats::predict(model, newdata=grid)
qplot(wt, mpg, data=mtcars, colour=factor(cyl)) + geom_line(data=grid)

# Example 3:
err <- stats::predict(model, newdata=grid, se = TRUE)
grid$ucl <- err$fit + 1.96 * err$se.fit
grid$lcl <- err$fit - 1.96 * err$se.fit
qplot(wt, mpg, data=mtcars, colour=factor(cyl)) +
  geom_smooth(aes(ymin = lcl, ymax = ucl), data=grid, stat="identity")