您可以将任何函数传递给map_*
方法,只要它遵循一些规则:1)它应该绘制在“当前”轴上,2)它应该采用两个向量作为位置参数,3)它应该接受color
关键字参数(如果您想与hue
选项)。
所以在你的情况下你只需要定义一点corrfunc
函数,然后将其映射到您想要注释的轴上:
import numpy as np
from scipy import stats
import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt
sns.set(style="white")
mean = np.zeros(3)
cov = np.random.uniform(.2, .4, (3, 3))
cov += cov.T
cov[np.diag_indices(3)] = 1
data = np.random.multivariate_normal(mean, cov, 100)
df = pd.DataFrame(data, columns=["X", "Y", "Z"])
def corrfunc(x, y, **kws):
r, _ = stats.pearsonr(x, y)
ax = plt.gca()
ax.annotate("r = {:.2f}".format(r),
xy=(.1, .9), xycoords=ax.transAxes)
g = sns.PairGrid(df, palette=["red"])
g.map_upper(plt.scatter, s=10)
g.map_diag(sns.distplot, kde=False)
g.map_lower(sns.kdeplot, cmap="Blues_d")
g.map_lower(corrfunc)