Vertical spaces in legend

Question

I am having trouble formatting my legend. I would like to increase the vertical space between each element of the legend.

I post the image it produces and the code so yo

Answer 1

When you consult the legend manual, for example by typing ?legend into your R console, you find

Arguments

...

x.intersp - character interspacing factor for horizontal (x) spacing.

y.intersp - the same for vertical (y) line distances.

To fix your legend, you could start with an interspacing factor of 2, so your legend call would become

legend("right", c(
    "$\\lambda < \\lambda_{cr}$ ",
    "$\\lambda < \\lambda_{cr}$",
    "$\\lambda = \\lambda_{cr}$ ",
    "$\\lambda = \\lambda_{cr}$ "
), xpd = TRUE, inset = c(0,0), bty = "n", lty = c(1, 1, 1, 1),
lwd=2, col = c("black","green4","red","blue"),
y.intersp=2)

If that gives you too much or too little space between the items, adjust the value accordingly.