R语言Plotly绘制Treemap树形图仅为最低层子节点按首数字配色咨询

我们可以通过先识别最低层级叶子节点、再对叶子节点按标签首数字做颜色映射的方式实现需求，非叶子节点会自动沿用原treemapcolorway配置的配色，具体步骤如下：

步骤1：预处理数据集，新增标识和颜色映射列 #

library(plotly)
library(stringr)

# 识别最低层级叶子节点：没有出现在parent列中的节点即为没有子节点的最低层级节点
df$is_leaf <- !df$label %in% df$parent

# 提取叶子节点标签开头的第一个数字
df$first_num <- ifelse(df$is_leaf, str_extract(df$label, "^\\d"), NA)

# 自定义首数字对应的配色，可根据需求自行调整色值
color_map <- c(
  "1" = "#FFB3BA", 
  "2" = "#BAFFC9", 
  "3" = "#BAE1FF", 
  "4" = "#FFFFBA", 
  "5" = "#FFD6BA", 
  "6" = "#E2BAFF", 
  "7" = "#FFB3F2", 
  "8" = "#B3FFF2", 
  "9" = "#D0D0D0" 
)

# 生成最终颜色向量：非叶子节点设为NA，沿用原有treemapcolorway配色，叶子节点使用映射颜色
df$node_color <- color_map[df$first_num]

步骤2：修改绘图代码，新增颜色参数 #

注意原代码中treemapcolorway的第四个色值少了#符号，下述代码已补全避免报错：

fig <- plot_ly(
    type = "treemap",
    labels = df$label,
    parents = df$parent,
    values = df$value / 1000,
    branchvalues = "total",
    texttemplate = "%{label}: %{value:.1f} TWh",
    textinfo = "label+value+percent parent+percent",
    # 新增节点颜色配置
    marker = list(
      colors = df$node_color
    )
  ) %>%
    layout(treemapcolorway = c("#FF0000", "#00A79F", "#413D3A", "#B51F1F", "#007480", "#CAC7C7"))

fig

补充说明 #

• 如果需要调整不同首数字对应的配色，直接修改color_map中的色值即可
• 若标签开头为两位及以上数字，只需将提取首数字的正则改为^\\d+，即可匹配完整开头数字序列再做映射

内容的提问来源于stack exchange，提问作者Jonas Schnidrig