Пример #1
0
def test_log_post_pred_k():

    np.random.seed(1)

    # Generate data
    D = 10
    N_1 = 10
    N_2 = 5
    N_3 = 5
    X = 5 * np.random.rand(N_1 + N_2 + N_3, D) - 1
    X_1 = X[:N_1]
    X_2 = X[N_1:N_1 + N_2]
    X_3 = X[N_1 + N_2:]

    # Prior
    var = 1 * np.random.rand(D)
    mu_0 = 5 * np.random.rand(D) - 2
    var_0 = 2 * np.random.rand(D)
    prior = FixedVarPrior(var, mu_0, var_0)
    precision = 1. / var
    precision_0 = 1. / var_0

    # Setup GMM
    assignments = np.concatenate(
        [np.zeros(N_1), np.ones(N_2), 2 * np.ones(N_3)])
    gmm = GaussianComponentsFixedVar(X, prior, assignments=assignments)

    # Remove everything from component 2 (additional check)
    for i in range(N_1, N_1 + N_2):
        gmm.del_item(i)

    # Calculate posterior for first component by hand
    x_1 = X_1[0]
    precision_N_1 = precision_0 + N_1 * precision
    mu_N_1 = (mu_0 * precision_0 +
              precision * N_1 * X_1.mean(axis=0)) / precision_N_1
    precision_pred = 1. / (1. / precision_N_1 + 1. / precision)
    expected_posterior = np.sum([
        log_norm_pdf(x_1[i], mu_N_1[i], 1. / precision_pred[i])
        for i in range(len(x_1))
    ])

    npt.assert_almost_equal(gmm.log_post_pred_k(0, 0), expected_posterior)

    # Calculate posterior for second component by hand
    x_3 = X_3[0]
    precision_N_3 = precision_0 + N_3 * precision
    mu_N_3 = (mu_0 * precision_0 +
              precision * N_3 * X_3.mean(axis=0)) / precision_N_3
    precision_pred = 1. / (1. / precision_N_3 + 1. / precision)
    expected_posterior = np.sum([
        log_norm_pdf(x_3[i], mu_N_3[i], 1. / precision_pred[i])
        for i in range(len(x_3))
    ])

    npt.assert_almost_equal(gmm.log_post_pred_k(N_1 + N_2, 1),
                            expected_posterior)
def test_log_post_pred_k():

    np.random.seed(1)

    # Generate data
    D = 10
    N_1 = 10
    N_2 = 5
    N_3 = 5
    X = 5*np.random.rand(N_1 + N_2 + N_3, D) - 1
    X_1 = X[:N_1]
    X_2 = X[N_1:N_1 + N_2]
    X_3 = X[N_1 + N_2:]

    # Prior
    var = 1*np.random.rand(D)
    mu_0 = 5*np.random.rand(D) - 2
    var_0 = 2*np.random.rand(D)
    prior = FixedVarPrior(var, mu_0, var_0)
    precision = 1./var
    precision_0 = 1./var_0

    # Setup GMM
    assignments = np.concatenate([np.zeros(N_1), np.ones(N_2), 2*np.ones(N_3)])
    gmm = GaussianComponentsFixedVar(X, prior, assignments=assignments)

    # Remove everything from component 2 (additional check)
    for i in range(N_1, N_1 + N_2):
        gmm.del_item(i)

    # Calculate posterior for first component by hand
    x_1 = X_1[0]
    precision_N_1 = precision_0 + N_1*precision
    mu_N_1 = (mu_0 * precision_0 + precision*N_1*X_1.mean(axis=0)) / precision_N_1
    precision_pred = 1./(1./precision_N_1 + 1./precision)
    expected_posterior = np.sum(
        [log_norm_pdf(x_1[i], mu_N_1[i], 1./precision_pred[i]) for i in range(len(x_1))]
        )

    npt.assert_almost_equal(gmm.log_post_pred_k(0, 0), expected_posterior)

    # Calculate posterior for second component by hand
    x_3 = X_3[0]
    precision_N_3 = precision_0 + N_3*precision
    mu_N_3 = (mu_0 * precision_0 + precision*N_3*X_3.mean(axis=0)) / precision_N_3
    precision_pred = 1./(1./precision_N_3 + 1./precision)
    expected_posterior = np.sum(
        [log_norm_pdf(x_3[i], mu_N_3[i], 1./precision_pred[i]) for i in range(len(x_3))]
        )

    npt.assert_almost_equal(gmm.log_post_pred_k(N_1 + N_2, 1), expected_posterior)
def test_log_prod_norm():

    np.random.seed(1)

    # Prior
    D = 10
    var = 1*np.random.rand(D)
    mu_0 = 5*np.random.rand(D) - 2
    var_0 = 2*np.random.rand(D)
    prior = FixedVarPrior(var, mu_0, var_0)

    # GMM will be used to access `_log_prod_norm`
    x = 3*np.random.rand(D) + 4
    gmm = GaussianComponentsFixedVar(np.array([x]), prior)

    expected_prior = np.sum([log_norm_pdf(x[i], mu_0[i], var_0[i]) for i in range(len(x))])

    npt.assert_almost_equal(gmm.log_prior(0), expected_prior)
Пример #4
0
def test_log_prod_norm():

    np.random.seed(1)

    # Prior
    D = 10
    var = 1 * np.random.rand(D)
    mu_0 = 5 * np.random.rand(D) - 2
    var_0 = 2 * np.random.rand(D)
    prior = FixedVarPrior(var, mu_0, var_0)

    # GMM will be used to access `_log_prod_norm`
    x = 3 * np.random.rand(D) + 4
    gmm = GaussianComponentsFixedVar(np.array([x]), prior)

    expected_prior = np.sum(
        [log_norm_pdf(x[i], mu_0[i], var_0[i]) for i in range(len(x))])

    npt.assert_almost_equal(gmm.log_prior(0), expected_prior)