Steamgraph in mpl

stacked_steamgraph_mpl.py

import numpy as np
import random as r
import matplotlib.pyplot as plt
def layers(n, m):
'function to generate some data'
    def bump(a):
        x = 1 / (.1 + r.random())
        y = 2 * r.random() - .5
        z = 10 / (.1+ r.random())
        for i in range(m):
            w = (i / float(m) - y) * z
            a[i] += x * np.exp(-w*w)
    a=np.zeros((m, n))
    for i in range(n):
        for j in range(5):            
            bump(a[:,i])
    return a 

n=15
d=layers(n,500)

#d_0=-np.sum(d,1)[:,None]*0.5
d_0=-1/(n+1.)*(d*(n-np.arange(1,n+1)[None,:]+1)).sum(1)[:,None]
d_s=np.cumsum(d,1)+d_0
plt.figure()
x=np.arange(d_s.shape[0])
c=plt.cm.coolwarm(np.linspace(0.1,0.5,n+1))
plt.fill_between(x, d_0.flat, d_s[:,0], interpolate=True,color=c[0])
for i in range(d_s.shape[1]-1):
    plt.fill_between(x,d_s[:,i],d_s[:,i+1], color=c[i+1], interpolate=True)