Visualization of realization of 2D dirichlet random variable with area plot that shows uncertainty.

Dirichlet_random_area_plot.py

import numpy as np
import scipy.stats as st
import matplotlib.pyplot as plt
plt.style.use('ggplot')

pmat = np.vstack([np.linspace(1, 20, 20), 
                  np.linspace(2, 10, 20), 
                  np.linspace(3, 5, 20)]).T

p = np.asarray([st.dirichlet.rvs(p_, 200) for p_ in pmat])

_, ax = plt.subplots(1, 1, figsize=(10, 5))
C = ['C0', 'C1', 'C2']
for j in range(200):
    pvec = p[:, j, :]
    pvec_ = np.hstack([np.zeros((20, 1)), np.cumsum(pvec, axis=1)])
    for i in range(3):
        ax.fill_between(np.arange(20), 
                        pvec_[:, i], 
                        pvec_[:, i+1], 
                        alpha=.01, 
                        facecolor=C[i]);

output.svg