r - 更改图例标题 ggplot

Question

如果不将我的形状和颜色分成两个单独的图例，我似乎无法更改图例标题。如何更改组合图例标题？图像就是图表的样子。

ggplot(data = df, aes (x = factor(dminp,c("-3 to -1", "-1 to 1")), y = sum_diff,col = factor(dmin), shape = factor(dmin), group = factor(dmin)))+
xlab("Range of Difficulty Parameters for Screen Items") + ylab("Bias Due to Skip-Logic") +
  stat_summary(geom = "point",fun.y = "mean",size = 8, aes(shape = factor(dmin)))+
  stat_summary(geom = "point",fun.y = "mean",size = 8, aes(col = factor(dmin)))+
 scale_shape_manual(values = c(8,5)) + theme_bw() + scale_colour_manual(values = c("orange","purple"))+
  theme(panel.grid.major.x  =   element_blank(),
        panel.grid.major =   element_line(colour = "black",size=0.25))+ theme(legend.justification = "top") 

我曾尝试使用 labs(col = "what i want it to be named") 但这会添加第二个图例并拆分形状/颜色。

标签： rggplot2

Answer 1

试试怎么样：

... +
scale_shape_manual(name="X",values = c(8,5)) + 
scale_colour_manual(name="X",values = c("orange","purple"))+
..

这是一个例子：

ggplot(iris,aes(x=Sepal.Width,y=Sepal.Length,shape=Species,col=Species)) + 
geom_point()+
scale_color_manual(name="X",values=c("Blue","Orange","Red")) + 
scale_shape_manual(name="X",values=c(17,18,19))