myVar = seq(-3, 3, .0001)              # Set up a variable with .0001 intervals
myNormVar = rnorm(myVar)               # Create random normal variable on myVar

png(filename = "illustrations/fig-5-2-kernel density.png",
  units = "in",                        # Set measurements in inches
  res = 1200,                          # Set resolution at 1200dpi
  width = 6,                           # Width at 6 inches
  height = 4)                          # Height at 4 inches

par(mai = c(1, 1, .25, .25))           # Set margins - no Title
                   
plot(density(myNormVar), main = NA)    # Density plot of normal variable
polygon(density(myNormVar), 
  col = "gray")                        # Fill it in with gray if you want

dev.off()                              # Output png file