在不同的seaborn或matplotlib图上分配命名的Colormap /调色板

Question

I have the following dummy data.

import seaborn as sb
import pandas as pd
import matplotlib.pyplot as pet

# Generate dummy data
a = np.random.random(70)
b = np.random.random(70) * 1.2
c = np.random.random(70) * 0.5 + 0.5
d = np.random.random(70) * 1.2 - 0.2

# Collate into a DataFrame
df = pd.DataFrame({'Control': a, 'Group1': b, 'Group2': c, 'Group3': d}) 
df = pd.melt(df) # Reshapes the data to allow for easy plotting with seaborn
df.columns = ['Group', 'value']

and I want to create 2 plots.

# Plot all data
sb.swarmplot(data = df, x = "Group", y = "value")

and

# Plot all data except `Group1`
sb.swarmplot(data = df[df["Group"] != "Group1"], x = "Group", y = "value")

As you can see, the color mapping between the 2 plots is inconsistent. How do I create a named Colormap or palette that can be parsed to the seaborn commands so the category-color mapping can be preserved?

Thank you in advance!

Answer 1

You can pass a dictionary:

pal = dict(Control="k", Group1="b", Group2="g", Group3="r")
sns.swarmplot(..., palette=pal)