如何在ggplot中对齐图例键和文本？

我希望这就是你想要的

library(ggplot2)

df = data.frame(
  x = c(1:10, 1:10),
  y = 1:20,
  group = rep(c('male', 'female'), each = 10))

ggplot(df, aes(x=x, y=y, color = group)) + 
  geom_smooth() +  
  theme(legend.position = 'right') + 
  guides(color = guide_legend(title.position = "top", 
                              # hjust = 0.5 centres the title horizontally
                              title.hjust = 0.5,
                              label.position = "left")) 
#> `geom_smooth()` using method = 'loess' and formula 'y ~ x'

^{由reprex软件包（v0.3.0）创建于2020-01-08}