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我知道已经有很多问题可以在多面图中添加 ggplot2 中的显着性水平。但是，作为 R 初学者，我没有找到适合我的情节的解决方案。我的数据（.txt 文件）可在此链接中找到：

1drv.ms/t/s!AsLAxDXdkA9Mg8oXdJ-qxD5AeB4KAw

有四列：三个因素水平（温度、寄生生物种类和行为）和一个数字水平（寄生数量和宿主杀死）。

我用代码运行情节：

    ggplot(mydata, aes(x = temperature, y = value, fill = species)) +  
facet_grid(. ~ behavior) +
stat_summary(fun.y = mean, geom = "bar", position = "dodge", stat="identity") +
stat_summary(fun.data = mean_sdl, fun.args = list(mult = 1) +
labs(x = "Temperature", y = "Nº of parasitized or host-killed larvae") +
theme(legend.position = "bottom", legend.title = element_blank(),  legend.text = element_text(size = 11, face = "italic"))

在此处输入图像描述

现在我想在每个图中添加显着性水平，分别比较两种温度下寄生和宿主杀死的结果。所以我在每个情节中有6个对比。我使用函数 stat_compare_means 测试了该选项。但是，正如本 Rblogger 教程 ( https://www.r-bloggers.com/add-p-values-and-significance-levels-to-ggplots/ ) 中所建议的，我应该列出我想要比较的内容。但是，在这种情况下，我有两个 25°C 的结果和两个 30°C 的结果。我如何创建这个提到所有对比的列表？如果有人能为我澄清如何解决这个问题，那将对我有很大帮助。谢谢。

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2 回答 2

2

stat_compare_means“开箱即用”工作（这是有道理的，因为它使用了ggplot函数中定义的分组。 

ggplot(mydata, aes(x = temp, y = value, fill = factor(species))) +  
  facet_grid(. ~ behavior) +
  stat_summary(fun.y = mean, geom = "bar", position = position_dodge(width = 1), stat="identity") +
  stat_summary(fun.data = mean_sdl, geom="errorbar", position = position_dodge(width = 1), width=0.25, stat="identity", fun.args = list(mult = 1)) +
                 labs(x = "Temperature", y = "Nº of parasitized or host-killed larvae") +
                 theme(legend.position = "bottom", legend.title = element_blank(),  legend.text = element_text(size = 11, face = "italic")) + 
  stat_compare_means(method = "t.test")

在此处输入图像描述

或者，切换 x 和 fill 变量：

ggplot(mydata, aes(x = factor(species), y = value, fill = factor(temp))) +  
  facet_grid(. ~ behavior) +
  stat_summary(fun.y = mean, geom = "bar", position = position_dodge(width = 1), stat="identity") +
  stat_summary(fun.data = mean_sdl, geom="errorbar", position = position_dodge(width = 1), width=0.25, stat="identity", fun.args = list(mult = 1)) +
  labs(x = "Temperature", y = "Nº of parasitized or host-killed larvae") +
  theme(legend.position = "bottom",  legend.text = element_text(size = 11, face = "italic")) + 
  stat_compare_means(method = "t.test")

在此处输入图像描述

于 2018-02-02T18:13:14.583 回答
0

Thanks @thc for your help and patience. As I decided to use letters over the error bars, I had to create a new data.frame for each letter and them add the geom_text. This got it right with the below code, after testing many x and y values to insert the letters in the right point. But certainly it has an easier way to do it that I don't know it. 

    sigvals1 <- data.frame(x=0.75,y=222.4, text=c("a"), behavior=c("Parasitism"))
    sigvals2 <- data.frame(x=1.207,y=190.55, text=c("a"), behavior=c("Parasitism"))
    sigvals3 <- data.frame(x=1.75,y=117.7, text=c("b"), behavior=c("Parasitism"))
    sigvals4 <- data.frame(x=2.209,y=103, text=c("b"), behavior=c("Parasitism"))
    sigvals5 <-data.frame(x = 0.75, y = 74.8, text=c("A"), behavior = c("Host-Killing"))
    sigvals6 <-data.frame(x = 1.20, y = 92.97, text=c("B"), behavior = c("Host-Killing"))
    sigvals7 <-data.frame(x = 1.74, y = 49.8, text=c("C"), behavior = c("Host-Killing"))
    sigvals8 <-data.frame(x = 2.196, y = 43, text=c("C"), behavior = c("Host-Killing"))

    plot + 
geom_text(data=sigvals1, aes(x=x,y=y, label=text, fill=NA), hjust=0) + 
      geom_text(data=sigvals2, aes(x=x,y=y, label=text, fill=NA), hjust=0) +
      geom_text(data=sigvals3, aes(x=x,y=y, label=text, fill=NA), hjust=0)+
      geom_text(data=sigvals4, aes(x=x,y=y, label=text, fill=NA), hjust=0) +
      geom_text(data=sigvals5, aes(x=x,y=y, label=text, fill=NA), hjust=0) +
      geom_text(data=sigvals6, aes(x=x,y=y, label=text, fill=NA), hjust=0) +
      geom_text(data=sigvals7, aes(x=x,y=y, label=text, fill=NA), hjust=0) +
      geom_text(data=sigvals8, aes(x=x,y=y, label=text, fill=NA), hjust=0)
于 2018-02-05T12:30:59.597 回答