How To Avoid Density Curve Getting Cut Off In Plot

Question

I am working on an assignment using R and the fitted density curve that is overlaid on the histogram is cut off at it's peak.

Example:

x <- rexp(1000, 0.2)
hist(x, prob = TRUE)
lines(density(x), col = "blue", lty = 3, lwd = 2)

I have done a search on the internet for this but didn't find anything addressing this problem. I have tried playing with the margins, but that doesn't work. Am I missing something in my code?

Thank you for your help!

Answer 1

Here's the simple literal answer to the question. Make an object to hold the result of your density call and use that to set the ylim of the histogram.

x <- rexp(1000, 0.2)
tmp <- density(x)
hist(x, prob = TRUE, ylim = c(0, max(tmp$y)))
lines(tmp, col = "blue", lty = 3, lwd = 2)

(should probably go to SO)