How to draw multiple contours in the same

Question

I am trying to get two contours in the same plot using ggplot2 in R.

Here is a reproducible example:

library(MASS)
library(ggplot2)
# first contour
m <- c(.0, -.0)
sigma <- matrix(c(1,.5,.5,1), nrow=2)
data.grid <- expand.grid(s.1 = seq(-3, 3, length.out=200), s.2 = seq(-3, 3, length.out=200))
q.samp <- cbind(data.grid, prob = mvtnorm::dmvnorm(data.grid, mean = m, sigma = sigma))

plot1 <- ggplot(q.samp, aes(x = s.1, y = s.2, z = prob)) +
  stat_contour(color = 'green')

# second contour
m1 <- c(1, 1)
sigma1 <- matrix(c(1,-.5,-.5,1), nrow=2)
set.seed(10)
data.grid1 <- expand.grid(s.1 = seq(-3, 3, length.out=200), s.2 = seq(-3, 3, length.out=200))
q.samp1 <- cbind(data.grid1, prob = mvtnorm::dmvnorm(data.grid1, mean = m1, sigma = sigma1))
plot2 <- ggplot(q.samp1, aes(x = s.1, y = s.2, z = prob)) +
  stat_contour(color = 'red')

However, trying plot1 + plot2 also does not work. Is there a way to get the two contours on the same plot.

Possible duplicate of [How to combine 2 plots (ggplot) into one plot?](https://stackoverflow.com/questions/21192002/how-to-combine-2-plots-ggplot-into-one-plot) — pogibas, Jul 19 '18 at 09:08

SeGa · Accepted Answer · 2018-07-19T09:20:30.587

1

What about including another stat_contour with different data?

ggplot(q.samp1, aes(x = s.1, y = s.2, z = prob)) +
  stat_contour(color = 'red') + 
  stat_contour(data = q.samp, aes(x = s.1, y = s.2, z = prob), color = 'green')

edited Jul 19 '18 at 09:20

answered Jul 19 '18 at 09:14

SeGa

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yeah.. I tried this but unfortunately this throws up an error - `Error: Don't know how to add o to a plot` – honeybadger Jul 19 '18 at 09:16

How to draw multiple contours in the same

1 Answers1