R 绘图 填充颜色
d <- density(mtcars$mpg)
plot(d, main="Kernel Density of Miles Per Gallon")

polygon(d, col="red", border="blue") # Filled Density Plot

d <- density(mtcars$mpg)
plot(d, main="Kernel Density of Miles Per Gallon")

polygon(d, col="red", border="blue") # Filled Density Plot
