Legend for plot with multiple densities

Question

I have the following code:

x <- seq(-25,25, by = .01)
plot(x, dunif(x,-10,10), type = 'l', ylab = 'probability', lwd = 2)
lines(x, dnorm(x,0,10), col = 'blue', lwd = 2)
lines(x, dstudent_t(x,4,0,10), col = 'red', lwd = 2)
lines(x, dcauchy(x,0,10), col = 'green', lwd = 2)
legend(1, 95, legend=c("Uniform (-10,10)", "Normal (0,10)", "Student t (4,0,10)", "Cauchy (0, 10)"),
       col=c("black", "red", "blue", "green"), lty=1:2, cex=0.8)

Which yields me the following plot:

But the legend doesn't show up and I am not sure where the error is.

Try `legend(-20, .04, legend=...)` or `legend("topleft", legend=...)`. — jay.sf, Nov 25 '19 at 12:43

score 1 · Answer 1 · answered Nov 25 '19 at 12:48

1

Try

legend(1, 0.05, legend=c("Uniform (-10,10)", "Normal (0,10)", "Student t (4,0,10)", "Cauchy (0, 10)"),
   col=c("black", "red", "blue", "green"), lty=1:2, cex=0.8)

Your y=95 value in the legend call is way outside the y-axis range.

answered Nov 25 '19 at 12:48

Valeri Voev

1,982
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Tried it but unfortunately overlapped slightly with one of the densities.. – RazorLazor Nov 25 '19 at 13:30

RazorLazor · Answer 2 · 2019-11-25T13:36:53.707

@jay.sf With your suggestion, the legend works! But the line it displays in the legend it sometimes dashed and sometimes not, how can i change it to a simple line for all distributions in the legend? (as for uniform and normal)

x <- seq(-25,25, by = .01)
plot(x, dunif(x,-10,10), type = 'l', ylab = 'probability', lwd = 2)
lines(x, dnorm(x,0,10), col = 'blue', lwd = 2)
lines(x, dstudent_t(x,4,0,10), col = 'red', lwd = 2)
lines(x, dcauchy(x,0,10), col = 'green', lwd = 2)
legend("topleft", legend=c("Uniform (-10,10)", "Normal (0,10)", "Student t (4,0,10)", "Cauchy (0, 10)"),
       col=c("black", "red", "blue", "green"), lty=1:2, cex=0.8)

edit: worked by putting:

lty=1

One last question. It seems like i cannot just assign the plot like this, as I usually do for ggplot to save it as a PDF. What's the option here?

plot1 <- plot(x, dunif(x,-10,10), type = 'l', ylab = 'probability', lwd = 2)
lines(x, dnorm(x,0,10), col = 'blue', lwd = 2)
lines(x, dstudent_t(x,4,0,10), col = 'red', lwd = 2)
lines(x, dcauchy(x,0,10), col = 'green', lwd = 2)
legend("topleft", legend=c("Uniform (-10,10)", "Normal (0,10)", "Student t (4,0,10)", "Cauchy (0, 10)"),
       col=c("black", "red", "blue", "green"), lty=1, cex=0.8)

Legend for plot with multiple densities

2 Answers2