Jointplot doesn't return handles and labels

[ISipi]

I noticed that when using

g = sns.jointplot(data=data, x="X", y="Y", hue="Group", kind="kde")

we don't get handles or labels when using
print(g.ax_joint.get_legend_handles_labels())

However, removing the "kind" keyword does print handles and labels - it doesn't matter what you insert as the input to "kind", but it always seems to override the handles and labels from "hue". Is there an easy fix for this?

[mwaskom]

Could you please provide a reproducible example? Thanks.

[ISipi]

Could you please provide a reproducible example? Thanks.

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


df = pd.DataFrame()
df['x'] = np.random.normal(2, 0.5, 200)
df['y'] = np.linspace(0, 1, 200)
df['group'] = np.random.choice(3, size=200)


g = sns.jointplot(data=df, x='x', y='y', hue='group')
print(g.ax_joint.get_legend_handles_labels())

g = sns.jointplot(data=df, x='x', y='y', hue='group', kind='kde')
print(g.ax_joint.get_legend_handles_labels())

[mwaskom]

I assume you want this data because you want to move the legend. (It can be helpful when opening an issue to provide context about what you're trying to do beyond the specific operation that isn't working). If that's the case I'd refer you to this issue.

Otherwise, this is not a bug from my perspective (nor does it have anything to do with jointplot, really): kdeplot does not add labeled artists to the axes, and that's what gets used when you specify kind="kde".

If you're trying to do some customization other than moving the legend it may be better to ask on stackoverflow.

[ISipi]

I actually wanted to change the labels in the legend for the kde-plot like this:

handles, labels = g.ax_joint.get_legend_handles_labels()
labels[2:] = ["Group 1", "Group 2", "Group 3", "Group 4"]
g.ax_joint.legend(handles=handles, labels=labels, title='Legend', fontsize=16)

In the above, the first two labels in labels are set by g.ax_joint.axhline.

I only managed to do this by not using kind='kde' and opting for

g = sns.jointplot(data=df, x='x', y='y', hue='group')
g.plot_joint(sns.kdeplot)

which does allow me to access the handles and labels for the kde-plot with g.ax_joint.get_legend_handles_labels().

So, an example of a working code in my instance:

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


df = pd.DataFrame()
df['x'] = np.random.normal(2, 0.5, 200)
df['y'] = np.linspace(0, 1, 200)
df['group'] = np.random.choice(3, size=200)

g = sns.jointplot(data=df, x='x', y='y', hue='group')
g.plot_joint(sns.kdeplot)

print(g.ax_joint.get_legend_handles_labels())

But this is not satisfactory, because it leaves the points from the sns.jointplot in the background.

[mwaskom]

So, an example of a working code in my instance

I don't think this example is "working", at least not in the way you want, because those are not handles for the KDE plot; they are handles for scatterplot points. See what happens when you try to recreate the legend with them:

g = sns.jointplot(data=df, x='x', y='y', hue='group')
g.plot_joint(sns.kdeplot)
g.ax_joint.legend(*g.ax_joint.get_legend_handles_labels())

I actually wanted to change the labels in the legend for the kde-plot like this

The officially-supported way to change the labels that seaborn adds is to send different data into its functions. Or you can manipulate the matplotlib objects after plotting. Unfortunately, the matplotlib legend object is less flexible than the Axes or the Artists that comprise the plot, but you can modify the legend text objects:

texts = g.ax_joint.legend_.texts
for t, label in zip(texts, "ABC"):
    t.set_text(label)

Closing as there's no bug here on the seaborn side.