如何管理plotly中子图中不同row_heights的legend_tracegroupgap？

Question

我找到了每个子图带有图例的子图示例代码。我通过添加 row_heights 来更改它，现在图例不适合子图。

import pandas as pd
import plotly.express as px

df = px.data.gapminder().query("continent=='Americas'")


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

fig = make_subplots(rows=3, cols=1, row_heights=[2,1,0.75]) 

fig.append_trace(go.Scatter(
    x=df.query("country == 'Canada'")['year'],
    y=df.query("country == 'Canada'")['lifeExp'],
    name = 'Canada',
    legendgroup = '1'
), row=1, col=1)
fig.append_trace(go.Scatter(
    x=df.query("country == 'United States'")['year'],
    y=df.query("country == 'United States'")['lifeExp'],
    name = 'United States',
    legendgroup = '1'
), row=1, col=1)

fig.append_trace(go.Scatter(
    x=df.query("country == 'Mexico'")['year'],
    y=df.query("country == 'Mexico'")['lifeExp'],
    name = 'Mexico',
    legendgroup = '2'
), row=2, col=1)
fig.append_trace(go.Scatter(
    x=df.query("country == 'Colombia'")['year'],
    y=df.query("country == 'Colombia'")['lifeExp'],
    name = 'Colombia',
    legendgroup = '2'
), row=2, col=1)
fig.append_trace(go.Scatter(
    x=df.query("country == 'Brazil'")['year'],
    y=df.query("country == 'Brazil'")['lifeExp'],
    name = 'Brazil',
    legendgroup = '2'
), row=2, col=1)

fig.append_trace(go.Scatter(
    x=df.query("country == 'Argentina'")['year'],
    y=df.query("country == 'Argentina'")['lifeExp'],
    name = 'Argentina',
    legendgroup = '3'
), row=3, col=1)
fig.append_trace(go.Scatter(
    x=df.query("country == 'Chile'")['year'],
    y=df.query("country == 'Chile'")['lifeExp'],
    name = 'Chile',
    legendgroup = '3'
), row=3, col=1)

fig.update_layout(
    height=800,
    width=800,
    title_text="Life Expectancy in the Americas",
    xaxis3_title = 'Year',
    yaxis1_title = 'Age',
    yaxis2_title = 'Age',
    yaxis3_title = 'Age',
    legend_tracegroupgap = 100,
    yaxis1_range=[50, 90],
    yaxis2_range=[50, 90],
    yaxis3_range=[50, 90]
)
fig.show()

现在我正在寻找一种解决方案来管理不同 row_heights 的 legend_tracegroupgap。我希望在子图旁边的顶部有图例。

Answer 1

从

Plotly v5.15

开始，您可以添加多个图例，并相对于绘图的高度定位它们。

在您的示例中，您可以将参数

legend='legend'

、

legend='legend2'

或

legend='legend3'

添加到每个

go.Scatter

以将它们与图例组匹配，然后将参数

legend = {"y": 1.0}, legend2 = {"y": 0.42},legend3 = {"y": 0.08}

添加到

fig.update_layout

。

以下是完整代码和结果图：

import pandas as pd
import plotly.express as px

df = px.data.gapminder().query("continent=='Americas'")


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

fig = make_subplots(rows=3, cols=1, row_heights=[2,1,0.75]) 

fig.append_trace(go.Scatter(
    x=df.query("country == 'Canada'")['year'],
    y=df.query("country == 'Canada'")['lifeExp'],
    name = 'Canada',
    legend='legend',
    legendgroup = '1'
), row=1, col=1)
fig.append_trace(go.Scatter(
    x=df.query("country == 'United States'")['year'],
    y=df.query("country == 'United States'")['lifeExp'],
    name = 'United States',
    legend='legend',
    legendgroup = '1'
), row=1, col=1)

fig.append_trace(go.Scatter(
    x=df.query("country == 'Mexico'")['year'],
    y=df.query("country == 'Mexico'")['lifeExp'],
    name = 'Mexico',
    legend='legend2',
    legendgroup = '2'
), row=2, col=1)
fig.append_trace(go.Scatter(
    x=df.query("country == 'Colombia'")['year'],
    y=df.query("country == 'Colombia'")['lifeExp'],
    name = 'Colombia',
    legend='legend2',
    legendgroup = '2'
), row=2, col=1)
fig.append_trace(go.Scatter(
    x=df.query("country == 'Brazil'")['year'],
    y=df.query("country == 'Brazil'")['lifeExp'],
    name = 'Brazil',
    legend='legend2',
    legendgroup = '2'
), row=2, col=1)

fig.append_trace(go.Scatter(
    x=df.query("country == 'Argentina'")['year'],
    y=df.query("country == 'Argentina'")['lifeExp'],
    name = 'Argentina',
    legend='legend3',
    legendgroup = '3'
), row=3, col=1)
fig.append_trace(go.Scatter(
    x=df.query("country == 'Chile'")['year'],
    y=df.query("country == 'Chile'")['lifeExp'],
    name = 'Chile',
    legend='legend3',
    legendgroup = '3',
), row=3, col=1)

fig.update_layout(
    height=800,
    width=800,
    title_text="Life Expectancy in the Americas",
    xaxis3_title = 'Year',
    yaxis1_title = 'Age',
    yaxis2_title = 'Age',
    yaxis3_title = 'Age',
    legend = {"y": 1.0},
    legend2 = {"y": 0.42},
    legend3 = {"y": 0.08},
    yaxis1_range=[50, 90],
    yaxis2_range=[50, 90],
    yaxis3_range=[50, 90]
)
fig.show()