Increase space between legend keys without increasing legend keys

Question

This is a follow-up on https://stackoverflow.com/questions/32275113

The problem is to tweak the legend elements to increase the space between legend keys without sim

Answer 1

One solution is to replace lines with points (requires additional geom layer):

Create plot with invisible points (size = 0 and rectangle shape shape = 15).

p <- ggplot(d, aes(x, ..density..)) + 
    geom_histogram(fill = "lightblue", color = "black") + 
    geom_vline(data = vlines, mapping = aes(xintercept = x, colour = stat)) +
    geom_point(data = vlines, aes(0, 0, colour = stat), size = 0, shape = 15)

Add legend theme to:

• Mask background color in legend (legend.key = element_rect(fill = "white"))
• Create large legend (legend.key.height = unit(3, "cm"))
• Remove lines (linetype = 0) and make large points (size = 5)

Code:

p + 
    theme(legend.direction = "vertical", 
          legend.position = "right",
          legend.key = element_rect(fill = "white"),
          legend.key.height = unit(3, "cm")) +
    guides(color = guide_legend(override.aes = list(linetype = 0, size = 5)))

PS.:

• This is not a perfect solution as there's a gap between legend label and boxes.
• If you want lines instead of rectangles use shape = 73