Seaborn lineplot legend not showing correct line colour – plotting two pandas series on one graph

Question

I’m trying to plot two data sets with Seaborn, this is my code.

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

sns.axes_style("ticks")

ss_data = pd.read_csv('A.csv')
ks_data = pd.read_csv('B.csv')

g = sns.lineplot(data=ks_data, x="K", y="pd", dashes=False)
sns.lineplot(data=ss_data, x="K", y="pd", dashes=False)
g.set_xticks(range(0,22,4))
plt.legend(labels=["A", "B"])
plt.savefig("test.png", dpi=500)

But this is the graph I am getting, as you can see, the legend doesn’t correctly show the line colour for B.

I think it’s probably due to the way that I am adding the second lineplot to the graph, but I couldn’t make it work any other way.

Asked By: redpanda2236

||

Source

Answer 1

Use the label parameter (passed to matplotlib.axes.Axes.plot()), and no need for plt.legend().

sns.lineplot(
    data=ks_data, x="K", y="pd", 
    label='A', errobar=None)
sns.lineplot(
    data=ss_data, x="K", y="pd", 
    label='B', errorbar=None)

Importantly, pass errorbar=None (or for seaborn versions prior to 0.12.0, ci=None), to turn off plotting of the confidence interval.

Answered By: BigBen

Answer 2

Maybe a matplotlib / seaborn version issue?
I’m not able to reproduce your graph. With some dummy data I get the expected results:

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

sns.axes_style("ticks")

data1 = {"K":[1,5,10,15,20], "pd":[2,10,20,30,40]}
data2 = {"K":[1,5,10,15,20], "pd":[1.5,9,18,16,35]}

ss_data = pd.DataFrame(data=data1)
ks_data = pd.DataFrame(data=data2)

g = sns.lineplot(data=ks_data, x="K", y="pd", dashes=False)
sns.lineplot(data=ss_data, x="K", y="pd", dashes=False)
g.set_xticks(range(0,22,4))
plt.legend(labels=["A", "B"])

I have seaborn == 0.11.2 and matplotlib==3.5.0

Answered By: Mat.B

Seaborn lineplot legend not showing correct line colour – plotting two pandas series on one graph

Question:

Answers: