示例#1
0
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()
示例#2
0
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()
示例#3
0
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()
示例#5
0
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()
示例#6
0
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()
示例#8
0
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()
示例#9
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    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)