如何基于0-1数值数组绘制灰度水平堆叠图及分类变量B配色实现

完整可运行代码 #

# 加载依赖包
library(tidyverse)
library(ggpubr)

# 构造示例数据，可替换为你实际的5万长度数组
df_wide <- tibble(
  ID = 1:10,
  Arr1 = c(0.1,0.1,0.1,0.2,0.2,0.2,0.7,0.7,0.4,0.7),
  Arr2 = c(0.6,0.6,0.6,0.1,0.1,0.1,0.1,0.1,0.5,0.1),
  Arr3 = c(0.3,0.3,0.3,0.7,0.7,0.7,0.2,0.2,0.1,0.2),
  Arr4 = c(0.4,0.6,0.7,0.2,0.1,0.3,0.4,0.5,0.3,0.9),
  B = c("a","a","a","b","b","b","a","a","a","b")
)

# 数值数组长表转换
df_num <- df_wide %>% 
  select(ID, Arr1:Arr4) %>% 
  pivot_longer(cols = -ID, names_to = "array", values_to = "value")

# 分类数组B长表转换
df_b <- df_wide %>% select(ID, B)

# 定义数值数组通用绘图函数
plot_num_array <- function(arr_name, color_low, color_high){
  df_num %>% 
    filter(array == arr_name) %>% 
    ggplot(aes(x = ID, y = 1)) +
    geom_tile(aes(fill = value), width = 1, height = 1) +
    scale_fill_gradient(low = color_low, high = color_high, limits = c(0,1)) +
    scale_y_continuous(breaks = NULL, name = arr_name) +
    theme_minimal() +
    theme(
      axis.title.x = element_blank(),
      axis.text.x = element_blank(),
      panel.grid = element_blank(),
      legend.position = "none"
    )
}

# 生成4个数值数组的绘图对象
# 如需灰度配色，可将color_low设为"white"，color_high设为"black"
p1 <- plot_num_array("Arr1", "#fff9cc", "#cc9900") # 浅黄到深黄
p2 <- plot_num_array("Arr2", "#e6f7ff", "#0050b3") # 浅蓝到深蓝
p3 <- plot_num_array("Arr3", "#f6ffed", "#389e0d") # 浅绿到深绿
p4 <- plot_num_array("Arr4", "#fff0f6", "#c41d7f") # 浅粉到深紫

# 生成分类数组B的绘图对象
p_b <- df_b %>% 
  ggplot(aes(x = ID, y = 1)) +
  geom_tile(aes(fill = B), width = 1, height = 1) +
  scale_fill_manual(values = c("a" = "green", "b" = "pink")) +
  scale_y_continuous(breaks = NULL, name = "B") +
  theme_minimal() +
  theme(
    axis.title.x = element_blank(),
    panel.grid = element_blank(),
    legend.position = "bottom"
  )

# 合并所有子图，垂直对齐x轴
ggarrange(p1, p2, p3, p4, p_b, ncol = 1, align = "v", heights = rep(1,5))

问题修复说明 #

• 选择geom_tile替代geom_col更适配按位置映射颜色的需求，对5万长度的大数据量兼容性更好，不会出现x轴刻度比例异常的问题
• 之前B数组绘图异常的核心原因是错误映射了color参数（仅控制边框颜色），改为映射fill参数即可实现整块填充
• 所有子图统一了x轴范围，合并时垂直对齐不会出现位置错位，可根据需求自行调整各个子图的配色、图例位置等参数

内容的提问来源于stack exchange，提问作者Rahil Vora