为具有单个组值的类别散点图添加平均线 [英] Add average lines for categorical scatterplots with single group values

问题描述

我有一个这样的分类散点图:

I have a categorical scatter plot like this:

:

data <- runif(50, 13, 17)
factors <- as.factor(sample(1:3, 50, replace = TRUE))
groups <- as.factor(sample(1:3, 50, replace = TRUE))
data_table <- data.frame(data, factors)
g <- ggplot(data_table, aes(y = data_table[, 1], x = data_table[, 2], colour = groups)) + geom_point(size = 1.5)

我试图为每个x-group添加一条平均线，但是我找不到正确的方法.我已经尝试使用此问题中所述的过程，但是它我认为这是行不通的，因为我的x组每个都由一个x值组成，因此我认为程序应该有所不同.

I am trying to add an average line for each x-group, but I can't manage to find the right way. I have already tried with the procedure described in this question, but it doesn't work, I reckon because my x-groups are composed of a single x-value each, for which I believe the procedure should be different.

如果要添加，请更详细地说明:

More in detail, if I add:

+ geom_line(stat = "hline", yintercept = "mean", aes(colour = data_table[, 2]))

在上一行代码中，出现以下错误: geom_path:每个组仅包含一个观察值.您是否需要调整组的审美?.

to the previous code line, it gives me the following error: geom_path: Each group consist of only one observation. Do you need to adjust the group aesthetic?.

如果我尝试执行该问题的答案中建议的步骤，请添加:

If I try with the procedure suggest in the answer to that question, by adding:

+ geom_errorbar(stat = "hline", yintercept = "mean", width=0.8, aes(ymax=..y..,ymin=..y..))

到我的初始代码(我删除了 geom_jitter(position = position_jitter(width = 0.4))的那段代码，因为它在我的数据图中添加了随机点)，我得到了三行每组(每个对应于特定x组的红色，绿色，蓝色三个组的平均值)，如下图所示:

to my initial code (I have removed the geom_jitter(position = position_jitter(width = 0.4)) piece of code, because it added random points to my data plot), I get three lines for each group (each corresponding to the mean of the three groups indicated in red, green, blue for that specifical x-group), as shown in this picture:

有人对如何解决此问题有任何建议吗?

Does anyone have any suggestion on how to fix this?

谢谢.

推荐答案

以下代码应为您提供所需的结果:

The following code should give you the desired result:

# creating reproducible data
set.seed(1)
data <- runif(50, 13, 17)
factors <- as.factor(sample(1:3, 50, replace = TRUE))
groups <- as.factor(sample(1:3, 50, replace = TRUE))
data_table <- data.frame(data, factors, groups)

# creating the plot
ggplot(data=data_table, aes(x=factor(factors), y=data, color=groups)) + 
  geom_point() +
  geom_errorbar(stat = "hline", yintercept = "mean", width=0.6, aes(ymax=..y.., ymin=..y.., group=factor(factors)), color="black")

给出:

检查方法是否正确:

> by(data_table$data, data_table$factors, mean)
data_table$factors: 1
[1] 15.12186
------------------------------------------------------------------------------------------------- 
data_table$factors: 2
[1] 15.03746
------------------------------------------------------------------------------------------------- 
data_table$factors: 3
[1] 15.24869

得出的结论是，均值已正确显示在图中.

which leads to the conclusion that the means are correctly displayed in the plot.

根据@rrs的建议，您也可以将其与箱形图组合:

Following the suggestion of @rrs, you could also combine it with a boxplot:

ggplot(data=data_table, aes(x=factor(factors), y=data, color=groups)) + 
  geom_boxplot(aes(middle=mean(data), color=NULL)) +
  geom_point(size=2.5)

给出:

但是，中线代表中位数，而不是均值.

However, the middle line represents the median and not the mean.

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