如何在ggplot中添加不同类别的平均值？

Question

我想在应用facet_wrap时添加4个类别（

2年* 2次治疗

）的平均值（文本或垂直线）。我已经尝试过

group_by

，但它只能适用于 2 个类别（年份或治疗）。是否可以对Year和Treatment进行平均值？

原始数据如下：

structure(list(Year = c(2021, 2021, 2021, 2021, 2021, 2021, 2021, 
2021, 2021, 2021, 2021, 2021, 2017, 2017, 2017, 2017, 2017, 2017, 
2017, 2017, 2017, 2017, 2017, 2017), Pos_heliaphen = c("W13", 
"W44", "X23", "Y42", "Z07", "Z36", "W45", "X22", "X30", "Y43", 
"Z06", "Z37", "Y36", "Z06", "Z18", "Z24", "Z40", "Z43", "Y35", 
"Z05", "Z17", "Z23", "Z39", "Z44"), Treatment = c("Non-irrigated", 
"Non-irrigated", "Non-irrigated", "Non-irrigated", "Non-irrigated", 
"Non-irrigated", "Irrigated", "Irrigated", "Irrigated", "Irrigated", 
"Irrigated", "Irrigated", "Non-irrigated", "Non-irrigated", "Non-irrigated", 
"Non-irrigated", "Non-irrigated", "Non-irrigated", "Irrigated", 
"Irrigated", "Irrigated", "Irrigated", "Irrigated", "Irrigated"
), Variety = c("ES Pallador - MG I", "ES Pallador - MG I", "ES Pallador - MG I", 
"Sultana - MG 000", "Sultana - MG 000", "Sultana - MG 000", "ES Pallador - MG I", 
"ES Pallador - MG I", "ES Pallador - MG I", "Sultana - MG 000", 
"Sultana - MG 000", "Sultana - MG 000", "ES Pallador - MG I", 
"ES Pallador - MG I", "ES Pallador - MG I", "Sultana - MG 000", 
"Sultana - MG 000", "Sultana - MG 000", "ES Pallador - MG I", 
"ES Pallador - MG I", "ES Pallador - MG I", "Sultana - MG 000", 
"Sultana - MG 000", "Sultana - MG 000"), SLA = c(127.105797101449, 
135.263238679969, 135.57233201581, 120.477777777778, 149.139664804469, 
139.5776, 142.927987742594, 139.450256889304, 152.589150943396, 
102.962703962704, 114.160714285714, 106.182042833608, 29.168895183201, 
61.5906086966241, 14.65223598377, 73.8218290951699, 29.0006487652397, 
37.6144729444593, 103.550713082565, 118.558911914481, 116.11947891962, 
91.7471974108231, 78.2428634817335, 91.5116772823779)), class = c("tbl_df", 
"tbl", "data.frame"), row.names = c(NA, -24L))

这是我的代码：

library(ggplot2)
library(dplyr)

df %>%
  mutate(across(Variety, factor, levels=c("Sultana - MG 000","ES Pallador - MG I","Isidor - MG I",
                                          "Santana - MG I/II","Blancas - MG II","Ecudor - MG II")))%>%
  ggplot(aes(y=Treatment,x=SLA,group=Year))+
  geom_point(aes(color = as.factor(Year),shape=Treatment),size=3,alpha = 0.7)+
  labs(x = expression(paste('SLA (cm'^2,'·','g'^-1,')')),
       y = "Treatment")+
  scale_color_manual(values = c("#FF6600","#336699"))+
  scale_shape_manual(values = c(16,1))+
  theme_bw() + 
  theme(axis.text.x = element_text(size=13,vjust=0.5),
        axis.text.y = element_text(size=13),
        axis.title.x = element_text(size = 14),
        axis.title.y = element_text(size = 14),
        legend.title=element_text(size=14),
        legend.text=element_text(size=12),
        legend.position = "bottom" )+
  guides(color = guide_legend(title = "Year"),shape = guide_legend(title = "Treatment"))+
  facet_wrap(~Variety)

这是我得到的图：

申请时如何填写每个品种这4个方框的平均值

facet_wrap

？

Answer 1

一种选择是使用

stat_summary

来计算平均值，并使用一个或两个

ifelse

有条件地定位两年的标签：

library(ggplot2)
library(dplyr)

df %>%
  mutate(across(Variety, factor, levels = c(
    "Sultana - MG 000", "ES Pallador - MG I", "Isidor - MG I",
    "Santana - MG I/II", "Blancas - MG II", "Ecudor - MG II"
  ))) %>%
  ggplot(aes(y = Treatment, x = SLA, group = Year)) +
  geom_point(aes(color = as.factor(Year), shape = Treatment), size = 3, alpha = 0.7) +
  stat_summary(
    geom = "label",
    fun = mean, orientation = "y",
    aes(
      y = as.numeric(factor(Treatment)) + .1 * if_else(Year == 2021, -1, 1),
      vjust = if_else(Year == 2021, 1, 0),
      label = after_stat(round(x, 1)),
      color = as.factor(Year)
    ),
    fill = NA
  ) +
  labs(
    x = expression(paste("SLA (cm"^2, "·", "g"^-1, ")")),
    y = "Treatment"
  ) +
  scale_color_manual(values = c("#FF6600", "#336699")) +
  scale_shape_manual(values = c(16, 1)) +
  theme_bw() +
  theme(
    axis.text.x = element_text(size = 13, vjust = 0.5),
    axis.text.y = element_text(size = 13),
    axis.title.x = element_text(size = 14),
    axis.title.y = element_text(size = 14),
    legend.title = element_text(size = 14),
    legend.text = element_text(size = 12),
    legend.position = "bottom"
  ) +
  guides(
    color = guide_legend(title = "Year"), 
    shape = guide_legend(title = "Treatment")) +
  facet_wrap(~Variety)