增加图例键之间的空间而不增加图例键

Question

这是对/sf/ask/2259257941/的跟进

问题是调整图例元素以增加图例键之间的空间,而无需同时扩展图例键本身.解决方案可能是调整正确的图例主题选项.

期望的结果:图例关键文本标签之间的垂直空间更大,但不延伸图例关键线.

d <- data.frame(x = mtcars$mpg, y = 0.10)
vlines <- rbind(aggregate(d[1], d[2], mean), 
                aggregate(d[1], d[2], median))
vlines$stat <- rep(c("mean", "median"), each = nrow(vlines)/2)
library("ggplot2")
ggplot(data = d, aes(x = x, y = ..density..)) + 
    geom_histogram(fill = "lightblue", color = "black") + 
    geom_vline(data = vlines, mapping = aes(xintercept = x, colour = stat), 
            show.legend = TRUE) +
    theme(legend.direction = "vertical", 
        legend.position = "right",
        #          legend.key = element_rect(size = 2),
        legend.key.size = unit(3, "cm"),
        #          legend.key.width = unit(2, "cm"),
        #          legend.key.height = unit(1, "cm")
        )

增加legend.key.size,如在回答所述链接的问题建议(见上文),具有增加的垂直线以及的不期望的副作用.

编辑基于PoGibas的巧妙解决方法,这里是所需结果的屏幕截图,包含在此处以确保目的明确:

继PoGibas,我用:shape = 73,legend.key.height = unit(2, "cm")和size = 6彩色引导内.

Answer 1

一种解决方案是用点替换线(需要额外的几何层):

使用不可见点(size = 0和矩形形状shape = 15)创建绘图.

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)

将图例主题添加到:

• 在传奇中掩盖背景颜色(legend.key = element_rect(fill = "white"))
• 创建大型图例(legend.key.height = unit(3, "cm"))
• 删除行(linetype = 0)并制作大点(size = 5)

码:

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:

• 这不是一个完美的解决方案,因为图例标签和方框之间存在差距.
• 如果你想要线而不是矩形使用 shape = 73