向图例添加额外项目

Question

我有以下数据：

trait,beta,se,p,analysis,signif
trait1,0.078,0.01,9.00E-13,group1,1
trait2,0.076,0.01,1.70E-11,group1,1
trait3,-0.032,0.01,0.004,group1,0
trait4,0.026,0.01,0.024,group1,0
trait5,0.023,0.01,0.037,group1,0
trait1,0.042,0.01,4.50E-04,group2,1
trait2,0.04,0.01,0.002,group2,1
trait3,0.03,0.01,0.025,group2,0
trait4,0.025,0.01,0.078,group2,0
trait5,0.015,0.01,0.294,group2,0
trait1,0.02,0.01,0.078,group3,0
trait2,0.03,0.01,0.078,group3,0
trait3,0.043,0.01,1.90E-04,group3,0
trait4,0.043,0.01,2.40E-04,group3,1
trait5,0.029,0.01,0.013,group3,0

使用以下代码制作情节：

library(ggplot2)
ggplot(GEE, aes(y=beta, x=reorder(trait, beta), group=analysis)) + 
  geom_point(data = GEE[GEE$signif == 1, ],
             color="red",
             shape = "*", 
             size=12, 
             show.legend = F) +
  geom_point(aes(color=analysis)) +
  geom_errorbar(aes(ymin=beta-2*se, ymax=beta+2*se,color=analysis), width=.2,
                position=position_dodge(.2)) +
  geom_hline(yintercept = 0) +
  theme_light() +
  theme(axis.title.y=element_blank(),
        legend.title=element_blank()) +
  coord_flip() 

这给了我以下情节：

我想在图例中添加一个额外的元素，即红色星号，我想让它说“重要”。我该怎么做呢？

PS。如果你喜欢这段代码，我还有另外一个问题，指定here：）

Answer 1

将虚拟aes()添加到geom_point - 例如填充名为重要aes(fill = "Significant")。

# Using OPs data
library(ggplot2)
ggplot(GEE, aes(y=beta, x=reorder(trait, beta), group=analysis)) + 
  geom_point(data = GEE[GEE$signif == 1, ],
             color="red",
             shape = "*", 
             size=12,
             aes(fill = "Significant")) +
  geom_point(aes(color=analysis)) +
  geom_errorbar(aes(ymin=beta-2*se, ymax=beta+2*se,color=analysis), width=.2,
                position=position_dodge(.2)) +
  geom_hline(yintercept = 0) +
  theme_light() +
  theme(axis.title.y=element_blank(),
        legend.title=element_blank()) +
  coord_flip() +
  guides(colour = guide_legend(order = 1), 
         fill = guide_legend(override.aes = list(size = 5))) +
  theme(legend.margin = margin(-0.5,0,0,0, unit="cm"))

PS：我还从asterik show.legend = F

中删除了geom_point