密谋：如何制作灰度饼图？

Question

这是绘制饼图的R代码

library(data.table)

# Data
data <- data.table(
  class = c("class 1", "class 2", "class 3", "class 4"),
  count = c(2403, 4949, 18, 570))

# Pie
data %>% plot_ly() %>% 
  add_trace(
    type = 'pie',
    labels = ~class, 
    values = ~count,
    marker = list(
      color = "rgb(211, 211, 211)",
      line = list(color = "rgb(20, 20, 20)", width = 1))
  ) %>% 
  layout(
    xaxis = list(showgrid = FALSE, zeroline = FALSE, showticklabels = FALSE),
    yaxis = list(showgrid = FALSE, zeroline = FALSE, showticklabels = FALSE))

当我需要灰度时会绘制一个“彩色”图表。

Answer 1

要获得关于类变量长度的灵活方法，您可以简单地使用：

colors = gray.colors(length(data$class))

情节1：

或者，如果您想要其他灰色调，则可以使用以下方式指定自己的颜色：

colors = list("rgb(80, 80, 80)", "rgb(120, 120, 120)", "rgb(160, 160, 160)", "rgb(160, 160, 160)")

图2：

完整代码：

library(data.table)
library(dplyr)
library(plotly)

# Data
data <- data.table(
  class = c("class 1", "class 2", "class 3", "class 4"),
  count = c(2403, 4949, 18, 570))

# Pie
data %>% plot_ly() %>% 
  add_trace(
    type = 'pie',
    labels = ~class, 
    values = ~count,
    marker = list(
      #colors = list("rgb(120, 120, 120)", "rgb(160, 160, 160)", "rgb(180, 180, 180)", "rgb(220, 220, 220)"),
      colors = gray.colors(length(data$class)),
      line = list(color = "rgb(20, 20, 20)", width = 1))
  ) %>% 
  layout(
    xaxis = list(showgrid = FALSE, zeroline = FALSE, showticklabels = FALSE),
    yaxis = list(showgrid = FALSE, zeroline = FALSE, showticklabels = FALSE))