p <- ggplot(mtcars, aesthetics=list(x=wt, y=mpg))


pdf("bar-line-point.pdf", height=6, width=6*4/3, version="1.4")
extra <- data.frame(wt=1:4 + 1, mpg=5:8 * 2)
ggline(ggpoint(ggbar(p, data=extra)), data=extra, size=5, colour=alpha("red", 0.5), aes=list(y=sqrt(mpg)+rnorm(4,20,3)))
dev.off()


pdf("text.pdf", height=6, width=6*4/3, version="1.4")
ggtext(ggplot(mtcars, aesthetics=list(x=wt, y=mpg, labels = rownames(mtcars))))
dev.off()


pdf("smooth.pdf", height=6, width=6*4/3, version="1.4")
ggsmooth(ggpoint(p))
dev.off()

pdf("histogram-density.pdf", height=6, width=6*4/3, version="1.4")
ggdensity(gghistogram(p, breaks=15), adjust=0.5, size=5, colour=alpha("darkgreen", 0.8))
dev.off()


pp <- function (n,r=4) {
  x <- seq(-r*pi, r*pi, len=n)
  df <- expand.grid(x=x, y=x)
  df$r <- sqrt(df$x^2 + df$y^2)
  df$z <- cos(df$r^2)*exp(-df$r/6)
  df
  }

pdf("tile.pdf", height=6, width=6*4/3, version="1.4")
scfillgradient(ggtile(ggplot(pp(100), aes=list(x=x,y=y,fill=z)))) 
dev.off()


pdf("aesthetics.pdf", height=6, width=6*4/3, version="1.4")
p2 <- ggpoint(p, aesthetics=list(colour=cyl, size=wt, shape=cyl))
pscontinuous(p2, "x", trans=trans_inverse)
dev.off()