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R语言 | 使用ggplot绘制柱状图，在柱子中显示数值和显著性

news 2025/7/17 21:53:29

原文链接：使用ggplot绘制柱状图，在柱子中显示数值和显著性

本期教程

获得本期教程示例数据，后台回复关键词：20240628。（PS：在社群中，可获得往期和未来教程所有数据和代码）

往期教程部分内容

写在前面

基于ggplot绘制柱状图，小技巧，很基础的图形。但是，越到后面，会发现，越是基础的图形，我们使用的频率越高。今天的教程是基于发芽指数来绘制，我们模拟一个发芽数和天数，计算出发芽指数。

代码

##'@在柱状图中显示数字
##'@2024.06.28
##'@
##'@小杜的生信笔记library(ggplot2)
library(dplyr)
library(tidyr)
library(ggplot2)
library(agricolae)setwd("D:\\BioinfoFile\\小杜的生信笔记\\2024\\20240628_柱状图中显示数据")
##'@此次数据基于种子发芽指数计算公式进行，数据具有随机性，不具有任何意义。
##'@加载数据
data <- read.csv("20240628_inputdata.csv",header = T)data

相关计算代码

## 转换数据
long_data <- data %>%pivot_longer(cols = starts_with("germinated"), names_to = "replicate", values_to = "germinated")
long_data
##计算活力指数
germination_index <- long_data %>%group_by(treatment, day) %>%summarise(GI = sum(germinated / day)) %>%ungroup()#'@计算各个处理的平均数和标准差
summary_gi <- germination_index %>%group_by(treatment) %>%summarise(mean_GI = mean(GI), sd_GI = sd(GI))#'@单因素方差分析
anova_result <- aov(GI ~ treatment + day, data = germination_index)
summary(anova_result)#'@进行Tukey HSD检验
tukey_result <- HSD.test(anova_result, "treatment", group = TRUE)
print(tukey_result)# 提取 Tukey HSD 结果中的字母标记
groups <- tukey_result$groups
df_letters <- data.frame(sample = rownames(groups), letters = groups$groups)
##'@修改名称
colnames(df_letters) <- c("treatment","letters")# 合并均值和字母标记
df_data <- merge(summary_gi, df_letters, by = "treatment")

绘图

ggplot(df_data, aes(x = treatment, y = mean_GI, fill = treatment)) +geom_bar(stat = "identity", position = "dodge", color = "black", size = 0.5) +##'@误差线geom_errorbar(aes(ymin = mean_GI - sd_GI, ymax = mean_GI + sd_GI), width = 0.15, ## 宽度size = 1  ##字体大小) +##'@显示数字geom_text(aes(x = treatment, y = mean_GI + sd_GI + 0.5,  ## “+0.5”显示的高度label = round(mean_GI, 2)),   ### "round(mean_GI, 2))",其中2，表示数字显示的小数点位数size = 5,color = 'black') +##'@显示显著性geom_text(aes(x = treatment, y = mean_GI + sd_GI + 1.3, label = letters), size = 6, color = "red") +theme_bw()+scale_fill_manual(values = c("#1f78b4", "#ff7f00", "#4daf4a")) +labs(x = NULL, y = "Germination Index")+theme(#axis.line = element_line(size = 1),  ## 粗细text=element_text(#family = "sans",colour ="black",size = 10),axis.text.x = element_text(color = "black", size = 12),axis.text.y = element_text(color = "black",size = 11),axis.ticks = element_line(colour = "black"),strip.text = element_text(color = "black",size = 10),axis.title = element_text(color = "black",size = 12), ##坐标轴字体大小legend.position = "none",strip.background = element_blank())ggsave("20240608_柱状图-显示数字.pdf",width = 6, height = 4)