向 ggplot 添加一个点会弄乱图例

Question

我有一个数据数据框

dat <- data.frame(cond = rep(c("A", "B"), each=10),
                  xvar = 1:20 + rnorm(20,sd=3),
                  yvar = 1:20 + rnorm(20,sd=3))

我想使用 ggplot2

散点图

假设附加点只是数据中的 15th 行

g1 <- dat[15,]

我现在可以生成绘图了

使用

scat1 <- ggplot(dat, aes(x=dat[,2], y=dat[,3], shape=factor(dat[,1]), size=2.5, 
     colour = factor(dat[,1]))) + geom_point(alpha=1)
#Add point to the plot 
scat1 <- scat1 + geom_point(x=g1[,2],y=g1[,3], 
colour="blue", size=4)   # this adds a blue point 
#here the legend goes awry and color changes to blue
#Add a label for the added point 
scat1 <- scat1 + geom_text(x=g1[,2], y=1+g1[,3], label="Added", col="Black") 
# this adds a label for the blue point
# Format the figure 
scat1 <- scat1 + theme(panel.grid.major = element_blank(),
         panel.grid.minor = element_blank(), 
         axis.text=element_text(size=14), 
         plot.title = element_text(size = rel(2), 
         colour = "black", face="bold"),
         axis.title=element_text(size=16,face="bold"),
         panel.background = element_blank(), 
         axis.line = element_line(colour = "black"),
         legend.text=element_text(size=14), 
         axis.text.x = element_blank(),
         legend.title=element_text(size=14),
         legend.justification = c(1, 1), 
         legend.position = c(0.25,1))
#Add sensible xlabel and ylabel 
scat1 <- scat1 + ylab(colnames(dat)[3]) +  xlab(colnames(dat)[2]) 
scat1 <- scat1 + ggtitle(paste("The variable", colnames(dat)[2], "and", colnames(dat)[3] )) 
#Delete multiple legends and add a suitable title to the legend
scat1 <- scat1 + guides(shape=guide_legend(title="sale year"), size=FALSE, 
          color= guide_legend(title="sale year"))

但是，我想将图例更改为与图像中原始颜色和形状匹配的形状和颜色，如下所示。我怎样才能做到这一点？

Answer 1

show_guide 会帮助你。请注意您在 aes 中定义事物的方式！只引用实际的变量名称（aes 中没有 dat）并将你想要设置（而不是映射）的东西移到 aes 调用之外。这也意味着您不必删除 size 的第二个图例。

ggplot(dat, aes(x = xvar, y = yvar, shape = cond, 
                         colour = cond), size = 2.5) + 
  geom_point(alpha = 1) +
  geom_point(data = g1, colour = "blue", size = 4, show_guide = FALSE)

向 ggplot 添加一个点会弄乱图例

Adding a point to the ggplot messes up the legend

r

graphics

plot

ggplot2

scatter-plot