def main(): # Load data X = pickle.load(open(data_fn, "rb")) N, D = X.shape # Model parameters alpha = 1. K = 4 # number of components mu_scale = 3.0 covar_scale = 1.0 # Sampling parameters n_runs = 2 n_iter = 12 # Intialize prior m_0 = np.zeros(D) k_0 = covar_scale**2 / mu_scale**2 v_0 = D + 3 S_0 = covar_scale**2 * v_0 * np.eye(D) prior = NIW(m_0, k_0, v_0, S_0) # Initialize component assignment: this is not random for testing purposes z = np.array([i * np.ones(N / K) for i in range(K)], dtype=np.int).flatten() # Setup FBGMM fbgmm = FBGMM(X, prior, alpha, K, assignments=z) print("Initial log marginal prob:", fbgmm.log_marg()) # Perform several Gibbs sampling runs and average the log marginals log_margs = np.zeros(n_iter) for j in range(n_runs): # Perform Gibbs sampling record = fbgmm.gibbs_sample(n_iter) log_margs += record["log_marg"] log_margs /= n_runs # Plot results fig = plt.figure() ax = fig.add_subplot(111) plot_mixture_model(ax, fbgmm) for k in range(fbgmm.components.K): mu, sigma = fbgmm.components.rand_k(k) plot_ellipse(ax, mu, sigma) # Plot log probability plt.figure() plt.plot(list(range(n_iter)), log_margs) plt.xlabel("Iterations") plt.ylabel("Log prob") plt.show()
def main(): # Load data X = pickle.load(open(data_fn, "rb")) N, D = X.shape # Model parameters alpha = 1. K = 2 # initial number of components mu_scale = 3.0 covar_scale = 1.0 # Sampling parameters n_runs = 1 n_iter = 100 # Intialize prior m_0 = np.zeros(D) k_0 = covar_scale**2/mu_scale**2 v_0 = D + 3 S_0 = covar_scale**2*v_0*np.eye(D) prior = NIW(m_0, k_0, v_0, S_0) # Initialize component assignment: this is not random for testing purposes z = np.array([i*np.ones(N/K) for i in range(K)], dtype=np.int).flatten() # Setup IGMM igmm = IGMM(X, prior, alpha, assignments=z) print("Initial log marginal prob:", igmm.log_marg()) # Perform several Gibbs sampling runs and average the log marginals log_margs = np.zeros(n_iter) for j in range(n_runs): # Perform Gibbs sampling record = igmm.gibbs_sample(n_iter) log_margs += record["log_marg"] log_margs /= n_runs # Plot results fig = plt.figure() ax = fig.add_subplot(111) plot_mixture_model(ax, igmm) for k in range(igmm.components.K): mu, sigma = igmm.components.rand_k(k) plot_ellipse(ax, mu, sigma) # Plot log probability plt.figure() plt.plot(list(range(n_iter)), log_margs) plt.xlabel("Iterations") plt.ylabel("Log prob") plt.show()
def main(): # Data parameters D = 2 # dimensions N = 100 # number of points to generate K_true = 4 # the true number of components # Model parameters alpha = 1. K = 3 # initial number of components n_iter = 20 # Generate data mu_scale = 4.0 covar_scale = 0.7 z_true = np.random.randint(0, K_true, N) mu = np.random.randn(D, K_true) * mu_scale X = mu[:, z_true] + np.random.randn(D, N) * covar_scale X = X.T # Intialize prior var_scale = 2. mu_0 = np.zeros(D) k_0 = covar_scale**2 / mu_scale**2 var = covar_scale**2 * np.ones(D) * var_scale var_0 = var / k_0 prior = FixedVarPrior(var, mu_0, var_0) # Setup IGMM igmm = IGMM(X, prior, alpha, assignments="rand", K=K, covariance_type="fixed") # Perform Gibbs sampling record = igmm.gibbs_sample(n_iter) # Plot results fig = plt.figure() ax = fig.add_subplot(111) plot_mixture_model(ax, igmm) for k in range(igmm.components.K): mu = igmm.components.rand_k(k) sigma = np.diag(var) plot_ellipse(ax, mu, sigma) plt.show()
def main(): # Data parameters D = 2 # dimensions N = 100 # number of points to generate K_true = 4 # the true number of components # Model parameters alpha = 1. K = 4 # number of components n_iter = 20 # Generate data mu_scale = 4.0 covar_scale = 0.7 z_true = np.random.randint(0, K_true, N) mu = np.random.randn(D, K_true)*mu_scale X = mu[:, z_true] + np.random.randn(D, N)*covar_scale X = X.T # Intialize prior var_scale = 0.5 # if you make this really small, you basically get k-means mu_0 = np.zeros(D) k_0 = covar_scale**2/mu_scale**2 var = covar_scale**2*np.ones(D)*var_scale var_0 = var/k_0 prior = FixedVarPrior(var, mu_0, var_0) # Setup FBGMM fbgmm = FBGMM(X, prior, alpha, K, "rand", covariance_type="fixed") # Perform Gibbs sampling record = fbgmm.gibbs_sample(n_iter) # Plot results fig = plt.figure() ax = fig.add_subplot(111) plot_mixture_model(ax, fbgmm) for k in range(fbgmm.components.K): mu = fbgmm.components.rand_k(k) sigma = np.diag(var) plot_ellipse(ax, mu, sigma) plt.show()
def main(): # Data parameters D = 2 # dimensions N = 100 # number of points to generate K_true = 4 # the true number of components # Model parameters alpha = 1. K = 3 # initial number of components n_iter = 20 # Generate data mu_scale = 4.0 covar_scale = 0.7 z_true = np.random.randint(0, K_true, N) mu = np.random.randn(D, K_true)*mu_scale X = mu[:, z_true] + np.random.randn(D, N)*covar_scale X = X.T # Intialize prior m_0 = np.zeros(D) k_0 = covar_scale**2/mu_scale**2 v_0 = D + 3 S_0 = covar_scale**2*v_0*np.eye(D) prior = NIW(m_0, k_0, v_0, S_0) # Setup IGMM igmm = IGMM(X, prior, alpha, assignments="rand", K=K) # igmm = IGMM(X, prior, alpha, assignments="one-by-one", K=K) # Perform Gibbs sampling record = igmm.gibbs_sample(n_iter) # Plot results fig = plt.figure() ax = fig.add_subplot(111) plot_mixture_model(ax, igmm) for k in range(igmm.components.K): mu, sigma = igmm.components.rand_k(k) plot_ellipse(ax, mu, sigma) plt.show()
def main(): # Data parameters D = 2 # dimensions N = 100 # number of points to generate K_true = 4 # the true number of components # Model parameters alpha = 1. K = 3 # initial number of components n_iter = 20 # Generate data mu_scale = 4.0 covar_scale = 0.7 z_true = np.random.randint(0, K_true, N) mu = np.random.randn(D, K_true)*mu_scale X = mu[:, z_true] + np.random.randn(D, N)*covar_scale X = X.T # Intialize prior m_0 = np.zeros(D) k_0 = covar_scale**2/mu_scale**2 v_0 = D + 3 S_0 = covar_scale**2*v_0*np.ones(D) prior = NIW(m_0, k_0, v_0, S_0) # Setup IGMM igmm = IGMM(X, prior, alpha, assignments="rand", K=K, covariance_type="diag") # igmm = IGMM(X, prior, alpha, assignments="one-by-one", K=K) # Perform Gibbs sampling record = igmm.gibbs_sample(n_iter) # Plot results fig = plt.figure() ax = fig.add_subplot(111) plot_mixture_model(ax, igmm) for k in xrange(igmm.components.K): mu, sigma = igmm.components.rand_k(k) plot_ellipse(ax, mu, np.diag(sigma)) plt.show()
def main(): # Data parameters D = 2 # dimensions N = 100 # number of points to generate K_true = 4 # the true number of components # Model parameters alpha = 1. K = 4 # number of components n_iter = 20 # Generate data mu_scale = 4.0 covar_scale = 0.7 z_true = np.random.randint(0, K_true, N) mu = np.random.randn(D, K_true) * mu_scale X = mu[:, z_true] + np.random.randn(D, N) * covar_scale X = X.T # Intialize prior m_0 = np.zeros(D) k_0 = covar_scale**2 / mu_scale**2 v_0 = D + 3 S_0 = covar_scale**2 * v_0 * np.ones(D) prior = NIW(m_0, k_0, v_0, S_0) # Setup FBGMM fbgmm = FBGMM(X, prior, alpha, K, "rand", covariance_type="diag") # Perform Gibbs sampling record = fbgmm.gibbs_sample(n_iter) # Plot results fig = plt.figure() ax = fig.add_subplot(111) plot_mixture_model(ax, fbgmm) for k in xrange(fbgmm.components.K): mu, sigma = fbgmm.components.rand_k(k) plot_ellipse(ax, mu, np.diag(sigma)) plt.show()
def main(): # Data parameters D = 2 # dimensions N = 100 # number of points to generate K_true = 4 # the true number of components # Model parameters alpha = 1. K = 4 # number of components n_iter = 20 # Generate data mu_scale = 4.0 covar_scale = 0.7 z_true = np.random.randint(0, K_true, N) mu = np.random.randn(D, K_true)*mu_scale X = mu[:, z_true] + np.random.randn(D, N)*covar_scale X = X.T # Intialize prior m_0 = np.zeros(D) k_0 = covar_scale**2/mu_scale**2 v_0 = D + 3 S_0 = covar_scale**2*v_0*np.eye(D) prior = NIW(m_0, k_0, v_0, S_0) # Setup FBGMM fbgmm = FBGMM(X, prior, alpha, K, "rand") # Perform Gibbs sampling record = fbgmm.gibbs_sample(n_iter) # Plot results fig = plt.figure() ax = fig.add_subplot(111) plot_mixture_model(ax, fbgmm) for k in range(fbgmm.components.K): mu, sigma = fbgmm.components.rand_k(k) plot_ellipse(ax, mu, sigma) plt.show()
def plot(self,ax,color='b'): #plot each component for j in xrange(self.n_comp): plot_utils.plot_ellipse(ax, self.mu[j], self.sig[j],color)