R语言Plotly子图自定义调色板配色不生效问题如何解决

失效原因 #

• 你在分组迭代的do()函数内给单条折线传入了3个颜色值，每个分组单独绘图时Plotly无法匹配对应颜色，导致配置不生效
• do()是dplyr已不推荐使用的旧语法，也可能存在兼容性问题

修复后的代码（推荐写法） #

我们先定义分组和自定义颜色的映射关系，分组绘图时自动匹配当前分组对应的颜色即可：

library(plotly)
library(dplyr)

# 自定义调色板，和分组值一一对应
palette <- c("a" = "blue", "b" = "red", "c" = "green")

data.frame(x = sample(letters[1:3],30,replace = TRUE)) %>%
  mutate(y = rnorm(30),
         z = runif(30,10,20)) %>%
  group_by(x) %>%
  # 用group_modify替代do做分组迭代
  group_modify(~{
    # 提取当前分组对应的颜色
    line_color <- palette[[cur_group()$x]]
    tibble(plot = list(
      plot_ly(.x, x = ~y, y = ~z, type = "scatter", mode = "lines",
              line = list(color = line_color))
    ))
  }) %>%
  pull(plot) %>%
  subplot(nrows = 1,
          shareX = FALSE,
          shareY = TRUE,
          margin = 0.0001)

如果你的分组是动态生成的，可以用分组序号取色，不需要提前写死分组名：

library(plotly)
library(dplyr)

palette <- c("blue", "red", "green")
data.frame(x = sample(letters[1:3],30,replace = TRUE)) %>%
  mutate(y = rnorm(30),
         z = runif(30,10,20)) %>%
  group_by(x) %>%
  group_modify(~{
    line_color <- palette[cur_group_id()]
    tibble(plot = list(
      plot_ly(.x, x = ~y, y = ~z, type = "scatter", mode = "lines",
              line = list(color = line_color))
    ))
  }) %>%
  pull(plot) %>%
  subplot(nrows = 1,
          shareX = FALSE,
          shareY = TRUE,
          margin = 0.0001)

内容的提问来源于stack exchange，提问作者MatCordTo