r - 如何将图例框一直移动到图的左侧并与 ggplot2 中的标题和副标题对齐？

Question

我有以下数据和图片设置如下

df <- data_frame(group = rep(c("A", "B"), each = 20),
       y = c(sample(1:90, 20, replace = TRUE),
             sample(1:30, 20, replace = TRUE)),
       x = rep(1:20, 2)
       )
ggplot(df, aes(x = x, y = y, color = group))+
   geom_line()+
   labs(x = "", y = "", title = "Comparison", 
     subtitle = "Unit (thousand)", 
     caption = "Source: Kaggle")+
   theme(legend.title = element_blank(), 
     legend.position = "top", 
     legend.justification='left',
     legend.box = "horizontal",
     legend.key = element_blank(),
     legend.box.margin = margin(0,0,0,0,"cm"),
     plot.title.position = "plot",
     plot.caption.position =  "plot",
     plot.caption = element_text(hjust = 0))

并在此处生成图表:



如何将图例框一直移动到情节的左侧并与标题和副标题对齐？还必须考虑到legend.key 中有一个边距。

如果您也可以让我知道如何减少图例周围的空间，也将不胜感激。谢谢!

Answer 1

这是指定 legend.position 的方法手动，以及添加 \n到副标题以创造额外的空间。您还需要 legend.direction = "horizontal"和 legend.margin = margin(0) :

请注意，您可能不得不摆弄 legend.position 中的数字。因为每个绘图设备都会略有不同。

ggplot(df, aes(x = x, y = y, color = group))+
   geom_line()+
   labs(x = "", y = "", title = "Comparison", 
     subtitle = "Unit (thousand)\n", 
     caption = "Source: Kaggle")+
   theme(legend.title = element_blank(), 
     legend.position = c(-0.065,1.05), 
     legend.justification='left',
     legend.box = "horizontal",
     legend.margin = margin(0),
     legend.key = element_blank(),
     legend.direction = "horizontal",
     plot.title.position = "plot",
     plot.caption.position =  "plot",
     plot.caption = element_text(hjust = 0))