13.20 调色板

plot_ly(iris,
  x = ~Petal.Length, y = ~Petal.Width,
  mode = "markers", type = "scatter",
  color = ~ Sepal.Length > 6, colors = c("#132B43", "#56B1F7")
)

plot_ly(iris,
  x = ~Petal.Length, y = ~Petal.Width, color = ~ Sepal.Length > 6,
  mode = "markers", type = "scatter"
)

plot_ly(iris,
  x = ~Petal.Length, y = ~Petal.Width, color = ~ Sepal.Length > 6,
  mode = "markers", type = "scatter", colors = "Set2"
)

plot_ly(iris,
  x = ~Petal.Length, y = ~Petal.Width, color = ~ Sepal.Length > 6,
  mode = "markers", type = "scatter", colors = "Set1"
)

构造 20 个类别 超出 Set1 调色板的范围，会触发警告说 Set1 没有那么多色块，但还是返回足够多的色块，也可以使用 viridis、plasma、magma 或 inferno 调色板

dat <- data.frame(
  dt = rep(seq(
    from = as.Date("2021-01-01"),
    to = as.Date("2021-01-31"), by = "day"
  ), each = 20),
  bu = rep(LETTERS[1:20], 31),
  qv = rbinom(n = 20 * 31, size = 10000, prob = runif(20 * 31))
)
# viridis
plot_ly(dat,
  x = ~dt, y = ~qv, color = ~bu, 
  mode = "markers", type = "scatter", colors = "viridis"
)

图 13.16: 调色板