multiple seaborn kdeplot plots with the same color bar

Question

I'm trying to plot two kde distributions on the same image and I'm wondering if there is a way to use the same "color range" for both distributions.

If you run the following code you'll see that the darkest red and the darkest green correspond to two different densities (0.04 and 0.15) while I would like to have both color scales with the same range so you can easily compare the two distributions (ie I would like to have the darkest red and the darkest green to correspond to the same density value).

Thank you

import numpy as np
import seaborn as sns
import pandas
import matplotlib.pyplot as plt
from matplotlib import rcParams

np.random.seed(10)
sns.set(color_codes=True)

rcParams['font.family'] = 'sans-serif'
rcParams['font.sans-serif'] = ['Arial']

plt.ioff()

f, ax = plt.subplots(figsize=(15, 15))
ax.tick_params(axis='both', which='major', labelsize=22)

mean, cov = [0, 2], [(2, 1), (.5, 1)]
x1, y1 = np.random.multivariate_normal(mean, cov, size=50).T

mean, cov = [5, 7], [(3, 2), (7, 1)]
x2, y2 = np.random.multivariate_normal(mean, cov, size=50).T

ax = sns.kdeplot(x1, y1, cmap="Reds",   shade=True, shade_lowest=False, alpha=0.66, legend=False, cbar=True)
ax = sns.kdeplot(x2, y2, cmap="Greens", shade=True, shade_lowest=False, alpha=0.66, legend=False, cbar=True)

plt.xlabel("foo", fontsize=22)
plt.ylabel("bar", fontsize=22)
plt.savefig("foo_vs_bar.png")

Answer 1

Probably too late, but I just had the same problem. You can specify levels in kwargs, eg

kwargs = {'levels': np.arange(0, 0.15, 0.01)}

and pass to sns.kdeplot():

ax = sns.kdeplot(x1, y1, cmap="Reds",   shade=True, shade_lowest=False,
             alpha=0.66, legend=False, cbar=True, **kwargs)