如何将散点和线 plot 与匹配的颜色和单个图例结合起来

Question

Looking at the following code

import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt
import numpy as np
plot_df = pd.DataFrame(index=np.arange(5), columns=["Series 1", "Series 2"], data=np.array([[1, 2],[2.4, 5],[4.1, 7.1],[5, 8.9],[5.2, 10]]))
plot_df_points = pd.DataFrame(index = [1.5, 2, 3.7], columns = ["Series 1", "Series 2"], data=np.array([[1.2, 3.4],[4.5, 6.9],[5.5, 9.6]]))
df = pd.DataFrame(plot_df.stack()).reset_index()
df.columns = ["x", "Series","y"]
df_points = pd.DataFrame(plot_df_points.stack()).reset_index()
df_points.columns = ["x", "Series","y"]
fig, ax = plt.subplots()
sns.lineplot(data=df,x="x",y="y", hue="Series",ax=ax,palette="rocket",linewidth=2.5)
sns.scatterplot(data=df_points, x="x", y="y", hue="Series", ax=ax,s=200)
plt.show()
plt.close()

I would like to have the same colour / legend for the same series. Ie the colour of series one in the line plot should be the same as in the scatter plot. How can this be achieved?

Answer 1

You need to set the same palette in the scatterplot as in the lineplot . Or use the default in both cases (leaving out palette= ).

To combine the legends, you can use the tuple legend handler ( HandlerTuple ).

import matplotlib.pyplot as plt
from matplotlib.legend_handler import HandlerTuple
import seaborn as sns
import pandas as pd
import numpy as np

plot_df = pd.DataFrame(index=np.arange(5), columns=["Series 1", "Series 2"],
                       data=[[1, 2], [2.4, 5], [4.1, 7.1], [5, 8.9], [5.2, 10]])
plot_df_points = pd.DataFrame(index=[1.5, 2, 3.7], columns=["Series 1", "Series 2"],
                              data=[[1.2, 3.4], [4.5, 6.9], [5.5, 9.6]])
df = plot_df.rename_axis('x').reset_index().melt(id_vars='x', var_name='Series', value_name='y')
df_points = plot_df_points.rename_axis('x').reset_index().melt(id_vars='x', var_name='Series', value_name='y')

fig, ax = plt.subplots()
sns.lineplot(data=df, x="x", y="y", hue="Series", ax=ax, palette="rocket", linewidth=2.5)
sns.scatterplot(data=df_points, x="x", y="y", hue="Series", ax=ax, palette="rocket", s=200)

handles, labels = ax.get_legend_handles_labels()
ax.legend([tuple(handles[::2]), tuple(handles[1::2])], labels[:2], handlelength=3,
          handler_map={tuple: HandlerTuple(ndivide=None)})

plt.tight_layout()
plt.show()