在子图中绘制条形图图例

Question

我想知道如何根据彩色条而不是单个跟踪图制作图例。在这种情况下，图例应基于'giraffes', 'orangutans', 'monkeys'。

import pandas as pd
import plotly.graph_objects as go
from plotly.subplots import make_subplots

fig = make_subplots(
    rows=1, 
    cols=3, 
    subplot_titles=('Zoo1',  'Zoo2', 'Zoo3'))

fig.add_trace(go.Bar(
    y=['giraffes', 'orangutans', 'monkeys'],
    x=[21, 15, 23],
    orientation='h',
    marker_color=["#00573C", '#9BD7BE', '#990012']),
    row=1, col=1)

fig.add_trace(go.Bar(
    y=['giraffes', 'orangutans', 'monkeys'],
    x=[15, 31, 23],
    orientation='h',
    marker_color=["#00573C", '#9BD7BE', '#990012']),
    row=1, col=2)

fig.add_trace(go.Bar(
    y=['giraffes', 'orangutans', 'monkeys'],
    x=[11, 32, 23],
    orientation='h',
    marker_color=["#00573C", '#9BD7BE', '#990012']),
    row=1, col=3)

fig.show()

Answer 1

Plotly 采用每个子图中最后一个条形的颜色并将其分配给图例，即绿色。要解决此问题，您可以更改构建子图的方式。我分别在每个子图中构建每个条形图，以便能够在图例中显示它，如下面的代码所示：

例子：

import pandas as pd
import plotly.graph_objects as go
from plotly.subplots import make_subplots

no_cols = 3
fig = make_subplots(
    rows=1, 
    cols=no_cols, 
    subplot_titles=('Zoo1',  'Zoo2', 'Zoo3'))

y=['giraffes', 'orangutans', 'monkeys', 'cat', 'dog'] 
x=[[15, 10, 6, 21, 43],[5, 10, 12, 21, 43],[30, 32, 23, 21, 44]] 
colors=["#00573C", '#9BD7BE', '#990012', '#9BD7BE', '#990012']

for i in range(1,no_cols+1):
    for value,animal,color in zip(x[i-1],y,colors):
        fig.add_trace(go.Bar(
            y=[animal],
            x=[value],
            orientation='h',
            marker_color=color, 
            name=animal,
            showlegend= i==len(y)),
            row=1, col=i)
    
fig.show()

输出：