如何在GGPLOT中的geom_jitter（）上添加geom_smooth（）或stat_smooth（）

Question

我有以下脚本：

require(datasets)
data(ToothGrowth)
library(ggplot2)
ToothGrowth$dose <- as.factor(ToothGrowth$dose)
p <- ggplot(ToothGrowth, aes(x=dose, y=len, color=dose, shape=dose)) + 
  geom_jitter(position=position_jitter(0.2))+
  labs(title="Plot of length  by dose",x="Dose (mg)", y = "Length") +   stat_summary(fun.data=mean_sdl, size=0.6, geom="pointrange", color="black") 
p + theme_classic() +
    theme(axis.line.x = element_line(colour = 'black', size=0.5, linetype='solid'),
          axis.line.y = element_line(colour = 'black', size=0.5, linetype='solid'))

这使得这个数字如下：

我的问题是如何为上面的黑色（平均）点添加smoothing line？

我尝试添加stat_smooth()但不起作用。

Answer 1

如果您将geom_smooth作为数字而不是将其作为一个因素，则可以通过dose直接执行此操作。对于颜色和形状映射，您可以使用factor(dose)或使用不同的名称创建新的分类剂量变量。

data(ToothGrowth)
# New categorical dose for shapes and colors
ToothGrowth$Dose <- factor(ToothGrowth$dose)

ggplot(ToothGrowth, aes(x = dose, y = len, color = Dose, shape = Dose)) + 
    geom_jitter(position=position_jitter(0.2))+
    labs(title="Plot of length  by dose",x="Dose (mg)", y = "Length") +   
    stat_summary(fun.data=mean_sdl, size=0.6, geom="pointrange", color="black")  + 
    theme_classic() +
    theme(axis.line.x = element_line(colour = 'black', size=0.5, linetype='solid'),
         axis.line.y = element_line(colour = 'black', size=0.5, linetype='solid')) +
    geom_smooth(aes(x = dose, y = len), inherit.aes = FALSE, se = FALSE)

如果你真的希望你的x轴是分类的，你需要通过在分类剂量变量上使用as.numeric来表示每个因子水平代表的整数的平滑线。这是使用x变量的 rank 而不是实际值来绘制平滑线，这在实际情况下可能有意义，也可能没有意义。

ToothGrowth$Dose <- factor(ToothGrowth$dose)

ggplot(ToothGrowth, aes(x = Dose, y = len, color = Dose, shape = Dose)) + 
    geom_jitter(position=position_jitter(0.2))+
    labs(title="Plot of length  by dose",x="Dose (mg)", y = "Length") +   
    stat_summary(fun.data=mean_sdl, size=0.6, geom="pointrange", color="black")  + 
    theme_classic() +
    theme(axis.line.x = element_line(colour = 'black', size=0.5, linetype='solid'),
         axis.line.y = element_line(colour = 'black', size=0.5, linetype='solid')) +
    geom_smooth(aes(x = as.numeric(Dose), y = len), inherit.aes = FALSE, se = FALSE)

Answer 2

require(datasets)
data(ToothGrowth)
library(ggplot2)
ToothGrowth$dose <- as.factor(ToothGrowth$dose)
p <- ggplot(ToothGrowth, aes(x=dose, y=len, color=dose, shape=dose)) + 
  geom_jitter(position=position_jitter(0.2))+
  labs(title="Plot of length  by dose",x="Dose (mg)", y = "Length") +   stat_summary(fun.data=mean_sdl, size=0.6, geom="pointrange", color="black") 
p + theme_classic() +
  theme(axis.line.x = element_line(colour = 'black', size=0.5, linetype='solid'),
        axis.line.y = element_line(colour = 'black', size=0.5, linetype='solid'))

lo <- loess(as.numeric(dose)~len,data=ToothGrowth)

p1 <- p+geom_line(aes(x=predict(lo)))