在R语言中绘制DataFrame折线图并自定义颜色

首先得把你的宽格式数据转成长格式，ggplot这类绘图工具更适配长格式数据：

library(tidyr)
library(ggplot2)

# 转换为ggplot可用的长格式
df_long <- pivot_longer(df, cols = -SUBJECT, names_to = "分组", values_to = "数值")

接下来自定义每个分组的折线颜色，只要颜色名称和分组名对应上，就能任意调整：

# 示例颜色，你可以替换成自己需要的十六进制色号或颜色名称
自定义颜色 <- c(
  "A" = "#ff4500", "B" = "#1e90ff", "C" = "#32cd32", "D" = "#ffd700",
  "E" = "#ff69b4", "F" = "#00fa9a", "G" = "#dc143c", "H" = "#4682b4",
  "I" = "#9370db", "L" = "#ff8c00", "M" = "#00ced1", "N" = "#f08080",
  "O" = "#adff2f", "P" = "#daa520", "Q" = "#98fb98", "R" = "#cd5c5c",
  "S" = "#6495ed", "T" = "#ffb6c1", "V" = "#87cefa"
)

然后就可以绘图了，想要更贴近Excel默认样式，还能借助ggthemes包的专属主题：

# 基础简洁版
ggplot(df_long, aes(x = SUBJECT, y = 数值, color = 分组, group = 分组)) +
  geom_line(linewidth = 1) + # 线宽贴近Excel默认
  scale_color_manual(values = 自定义颜色) + # 应用自定义颜色
  labs(x = "受试者", y = "数值", title = "各分组折线图") +
  theme_minimal() +
  theme(
    plot.title = element_text(hjust = 0.5), # 标题居中
    legend.position = "right", # 图例放右侧，和Excel一致
    axis.text = element_text(size = 10),
    axis.title = element_text(size = 12)
  )

# 高度仿Excel版（需先安装包：install.packages("ggthemes")）
library(ggthemes)
ggplot(df_long, aes(x = SUBJECT, y = 数值, color = 分组, group = 分组)) +
  geom_line(linewidth = 1) +
  scale_color_manual(values = 自定义颜色) +
  labs(x = "受试者", y = "数值", title = "各分组折线图") +
  theme_excel() +
  theme(plot.title = element_text(hjust = 0.5))

如果你的Excel原图还有数据点、特定网格线这类细节，添加geom_point()就能显示数据点，调整theme里的panel.grid.major/panel.grid.minor参数就能修改网格线样式。

内容的提问来源于stack exchange，提问作者Ed9012