# how to overlay a line plot with a density plot? (R, ggplot2)

by Y Zhang   Last Updated January 13, 2018 00:26 AM

Hi how do I overlap the following curves in one graph? Any help's appreciated. Thank you!

``````library(ggplot2)

x = -10:10
y = dnorm(x, mean=0, sd=3)
df.norm = data.frame('x'=x, 'y'=y)

ggplot(data=df.norm, aes(x=x, y=y)) +
geom_line() +
geom_point()

random = data.frame('x'=rnorm(1000, mean = 0, sd = 3))

ggplot(random, aes(x=x)) +
geom_density(size=1)
``````

I tried the following and it didn't work

``````ggplot(data=df.norm, aes(x=x, y=y)) +
geom_line() +
geom_point() +
geom_density(random, aes(x=x), size=1)
``````
Tags :

``````library(ggplot2)

x = -10:10
y = dnorm(x, mean=0, sd=3)
df.norm = data.frame('x'=x, 'y'=y)

random = data.frame('x'=rnorm(1000, mean = 0, sd = 3))

ggplot() +
geom_line(data=df.norm, aes(x=x, y=y)) +
geom_point(data=df.norm, aes(x=x, y=y)) +
geom_density(data=random, aes(x=x), size=1)
``````

scoa
July 09, 2015 09:19 AM

ggplot2

A more concise version in ggplot2 using the argument `inherit.aes = FALSE` to overrides the default aesthetics used in the previous two layers.

``````library(ggplot2)
set.seed(2017)
x = -10:10
y = dnorm(x, mean = 0, sd = 3)
df.norm = data.frame('x' = x, 'y' = y)
random = data.frame('x' = rnorm(1000, mean = 0, sd = 3))

ggplot(data = df.norm, aes(x = x, y = y)) +
geom_line() +
geom_point() +
geom_density(data = random,
aes(x = x),
inherit.aes = FALSE,
size = 1)
``````

Base

Adapting the solution provided by scoa to the base package:

``````plot(df.norm, type = "l", bty = "n", las = 1)
points(df.norm, pch= 19)
lines(density(random\$x), lwd = 2)
``````

Adding a legend, and a different colour for the density curve:

``````plot(df.norm, type = "l", bty="n", las = 1)
points(df.norm, pch= 19)
lines(density(random\$x), lwd =2, col = 'orange')
legend(x = "topleft",
c("df.norm", "Density plot"),
col = c("black", "orange"),
lwd = c(2, 2),
bty = "n")
``````

mpalanco
July 15, 2015 08:33 AM