from scipy import stats
import matplotlib.pyplot as plt
import numpy as np

plt.style.use('ggplot')
fig, ax = plt.subplots(facecolor="w", figsize=(10, 5))

x = np.linspace(0.000001, 10, 1000) # X axis
f_df = [(5,5), (5,10), (5,20), (10,5), (20,5), (10,10), (20,20)] # degree of freedom of F(m,n)

for i in range(len(f_df)):
    y = stats.f.pdf(x, f_df[i][0], f_df[i][1])
    ax.plot(x, y, linestyle='-', label=f'F({f_df[i][0]}, {f_df[i][1]})', lw=5, alpha=0.5)

plt.xlim(0, 5)
plt.ylim(0, 1.0)
plt.legend()
plt.show()