Julia：如何在散点图中更改组的颜色

Question

假设我有以下示例代码

using PlotlyJS
using CSV, DataFrames

df = dataset(DataFrame, "iris")
plot(
    df, x=:sepal_width, y=:sepal_length, color=:species,
    mode="markers"
)

我该如何为每个组指定颜色，例如如果我想让 setosa 变成黄色？

正是这个Plotly-Express: How to fix the color mapping when setting color by column name 但我在 julia 需要它。我无法让 color_discrete_map 工作...

Answer 1

不像设置color_discrete_map那么方便，但你可以这样做：

julia> species_color_map = Dict("setosa"     => "yellow",
                                "versicolor" => "aqua",
                                "virginica"  => "red")
Dict{String, String} with 3 entries:
  "virginica"  => "red"
  "setosa"     => "yellow"
  "versicolor" => "aqua"

julia> plot([scatter(
           subdf,
           x = :sepal_width,
           y = :sepal_length,
           name = subdf[1, :species],
           marker_color = species_color_map[ subdf[1, :species] ],
           mode = "markers"
       )
       for subdf in groupby(df, :species)])

这几乎就是plot(df, ..., color=:species) 调用对underneath 所做的，以更通用的方式。不幸的是，我没有办法插入它，只是根据值自定义颜色。