不同颜色的 Altair 选择

Question

我今天开始玩 Altair，对选择有疑问。我创建了 3 个不同颜色的条形图，如下所示。现在，每当我单击一个条形图时，我都希望在其他两个条形图中突出显示等效项。如果我不使用任何颜色并且默认为蓝色，这会很好用，但我不知道如何在选择中保留我的颜色而不是所有 3 个图表都使用相同的颜色。

df = pd.DataFrame({"Name":["Bulbasaur", "Charizard", "Mewtwo"], 
                  "HP":[45, 80, 100], 
                  "Attack":[30, 50, 60], 
                  "Defense":[40, 38, 42], 
                  "Type":["Grass", "Fire", "Psychic"]}) 


selection = alt.selection_single(fields=["Type 1"])

# This doesn't do much as I don't have a column named #73a1eb. But it's the colour code I'd like to use.
color1 = alt.condition(selection,
                  alt.Color("#73a1eb:N", legend=None), 
                  alt.value('lightgray'))

color2 = alt.condition(selection,
                  alt.Color("#73b9c7:N", legend=None),
                  alt.value('lightgray'))

color3 = alt.condition(selection,
                  alt.Color("#d7abf5:N", legend=None),
                  alt.value('lightgray'))

# The mark bar colour is overriden by color in encode

chart1 = alt.Chart(df, title="Average HP by Type")
            .mark_bar(color="#73a1eb", size = 12)
            .encode(x = 'mean(HP):Q',
                    y = alt.Y('Type 1:N', sort='-x'), 
                    tooltip=["Type 1", "mean(HP):Q"], 
                    color=color1)
            .properties(height=320,
                        width=300)
            .add_selection(selection)

chart2 = alt.Chart(df, title="Average Attack by Type")
            .mark_bar(color="#73a1eb", size = 12)
            .encode(x = 'mean(Attack):Q',
                    y = alt.Y('Type 1:N', sort='-x'), 
                    tooltip=["Type 1", "mean(HP):Q"], 
                    color=color1)
            .properties(height=320,
                        width=300)
            .add_selection(selection)

chart2 = alt.Chart(df, title="Average Defense by Type")
            .mark_bar(color="#73a1eb", size = 12)
            .encode(x = 'mean(Defense):Q',
                    y = alt.Y('Type 1:N', sort='-x'), 
                    tooltip=["Type 1", "mean(HP):Q"], 
                    color=color1)
            .properties(height=320,
                        width=300)
            .add_selection(selection)

alt.hconcat(chart1, chart2, chart3).configure_axis(grid=False).configure_axisBottom().resolve_scale(x = 'shared')

Answer 1

当您写 alt.Color("#73a1eb:N") 时，这意味着您希望颜色根据名为 "#73a1eb" 的列进行编码，该列具有标称 ("N") 类型。

您似乎想要指定颜色值而不是颜色编码，在这种情况下您可以写alt.value("#73a1eb")。所以你的情况看起来像这样：

color1 = alt.condition(selection,
                       alt.value("#73a1eb"),
                       alt.value('lightgray'))

不同颜色的 Altair 选择

Altair selection with different colours

python

altair