Skip to content
{{ message }}

Instantly share code, notes, and snippets.

# monochromegane/dgp.py

Created Mar 11, 2020
Plot Gamma-Poisson model and Dynamic Gamma-Poisson model
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
 import argparse import math import numpy as np import matplotlib.pyplot as plt from matplotlib import animation def pdf_gamma(x, k, lambda_): return (math.pow(lambda_, k)/math.gamma(k)) * math.pow(x, k-1) * math.exp(-lambda_*x) def plot_gamma(ax, alpha, gamma, title): plot_x = np.arange(0.01, 1.0, 0.01) y = [pdf_gamma(x, alpha, gamma) for x in plot_x ] ax.set_title(title) ax.axvline(alpha/gamma, color='C1', linestyle='--') ax.set_ylim(0, 15) ax.plot(plot_x, y, color='C0') def update(i): global alpha, gamma, d_alpha, d_gamma, ctr if i != 0: axes[0].clear() axes[1].clear() if i == 20: ctr /= 2 title = r'{}: [{:0>2}] $\lambda$={:.2f}, E(X)={:.2f}' X = [np.random.poisson(lam=ctr) for _ in range(args.view) ] c = sum(X) alpha += c gamma += args.view plot_gamma(axes[0], alpha, gamma, title.format('Gamma-Poisson', i, ctr, alpha/gamma)) d_alpha *= args.delta d_alpha += c d_gamma *= args.delta d_gamma += args.view plot_gamma(axes[1], d_alpha, d_gamma, title.format(r'Dynamic Gamma-Poisson($\delta$={:.2f})'.format(args.delta), i, ctr, d_alpha/d_gamma)) parser = argparse.ArgumentParser() parser.add_argument("--lambda_", type=float, default=0.4) parser.add_argument("--view", type=int, default=7) parser.add_argument("--delta", type=float, default=0.9) args = parser.parse_args() ctr = args.lambda_ alpha = 1 gamma = 1 d_alpha = 1 d_gamma = 1 fig, axes = plt.subplots(nrows=2, sharex=True) ani = animation.FuncAnimation(fig, update, frames=np.arange(0, 50), interval=200) ani.save('animate.gif', writer='pillow')
to join this conversation on GitHub. Already have an account? Sign in to comment