Ejemplo n.º 1
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def mutual_info_p(a, b):
    """ Fast mutual information calculation based upon sklearn,
    but with estimation of uncertainty from Lin & Tegmark 2016
    """
    # contingency matrix of a * b
    contingency = contingency_matrix(a, b, sparse=True)
    nzx, nzy, Nall = sp.find(contingency)
    N = len(a)
    # entropy of a
    Na = np.ravel(contingency.sum(axis=0))
    S_a, var_a = entropyp(Na / np.sum(Na))

    # entropy of b
    Nb = np.ravel(contingency.sum(axis=1))
    S_b, var_b = entropyp(Nb / np.sum(Nb))

    # joint entropy
    S_ab, var_ab = entropyp(Nall / N)

    # mutual information
    MI = S_a + S_b - S_ab

    # uncertainty and variance of MI
    MI_var = var_a + var_b + var_ab

    uncertainty = np.sqrt((MI_var) / len(a))

    return MI, uncertainty
Ejemplo n.º 2
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def g_score(y_true, y_pred, eps=None, sparse=False):
    """ G-score

        Calculates the G-score: sqrt(prod(true_rates)).

        Parameters
        ----------
        y_true: array-like, shape = [n_samples]
                Ground truth (correct) target values.
        y_pred: array-like, shape = [n_samples]
                Estimated targets as returned by a classifier.
        eps: None or float, optional.
             If a float, that value is added to all values in the contingency
             matrix. This helps to stop NaN propagation. If ``None``, nothing is
             adjusted.
        sparse: boolean, optional.
                If True, return a sparse CSR continency matrix. If ``eps is not
                None``, and ``sparse is True``, will throw ValueError.

        Returns
        -------
        g: float
           G-score.
    """
    y_true, y_pred = check_clusterings(y_true, y_pred)
    c = contingency_matrix(y_true, y_pred, eps=eps, sparse=sparse)
    d = c.diagonal()
    true_rates = d.reshape([len(d), 1]) / c.sum(axis=1).ravel()
    g = np.prod(true_rates)**(1.0 / c.shape[0])
    return g
Ejemplo n.º 3
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def rand_index_score(labels_true, labels_pred):

    # check clusterings
    labels_true, labels_pred = check_clusterings(labels_true, labels_pred)

    # initial statistics calculations
    n_samples = labels_true.shape[0]
    n_samples_comb = comb(n_samples, 2)
    n_classes = np.unique(labels_true).shape[0]
    n_clusters = np.unique(labels_pred).shape[0]
    class_freq = np.bincount(labels_true)
    cluster_freq = np.bincount(labels_pred)

    # Special limit cases: no clustering since the data is not split;
    # or trivial clustering where each document is assigned a unique cluster.
    # These are perfect matches hence return 1.0.
    if (n_classes == n_clusters == 1 or n_classes == n_clusters == 0
            or n_classes == n_clusters == n_samples):
        return 1.0

    # Compute the RI using the contingency data
    contingency = contingency_matrix(labels_true, labels_pred, sparse=True)
    sum_comb_c = sum((n_c**2) for n_c in cluster_freq)
    sum_comb_k = sum((n_k**2) for n_k in class_freq)
    sum_comb = sum((n_ij**2) for n_ij in contingency.data)

    return (1 +
            (sum_comb - 0.5 * sum_comb_k - 0.5 * sum_comb_c) / n_samples_comb)
Ejemplo n.º 4
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def est_mutual_info_p(a, b):
    # contingency matrix of a * b
    contingency = contingency_matrix(a, b, sparse=True)
    nzx, nzy, Nall = sp.find(contingency)

    # entropy of a
    Na = np.ravel(contingency.sum(axis=0))  # number of A
    S_a, var_a = entropyp(Na)  # entropy with P(A) as input

    # entropy of b
    Nb = np.ravel(contingency.sum(axis=1))
    S_b, var_b = entropyp(Nb)

    # joint
    S_ab, var_ab = entropyp(Nall)

    # mutual information
    MI = S_a + S_b - S_ab

    # uncertainty and variance of MI
    MI_var = var_a + var_b + var_ab

    uncertainty = np.sqrt((MI_var) / len(a))

    return MI, uncertainty
def mutual_info_score(labels_true, labels_pred, contingency=None):
    if contingency is None:
        labels_true, labels_pred = check_clusterings(labels_true, labels_pred)
        contingency = contingency_matrix(labels_true, labels_pred, sparse=True)
    else:
        contingency = check_array(contingency,
                                  accept_sparse=['csr', 'csc', 'coo'],
                                  dtype=[int, np.int32, np.int64])
    if isinstance(contingency, np.ndarray):
        nzx, nzy = np.nonzero(contingency)
        nz_val = contingency[nzx, nzy]
    elif sp.issparse(contingency):
        nzx, nzy, nz_val = sp.find(contingency)
    else:
        raise ValueError("Unsupported type for 'contingency': %s" %
                         type(contingency))
    contingency_sum = contingency.sum()
    pi = np.ravel(contingency.sum(axis=1))
    pj = np.ravel(contingency.sum(axis=0))
    log_contingency_nm = np.log2(nz_val)
    contingency_nm = nz_val / contingency_sum
    outer = pi.take(nzx) * pj.take(nzy)
    log_outer = -np.log2(outer) + log2(pi.sum()) + log2(pj.sum())
    mi = (contingency_nm * (log_contingency_nm - log2(contingency_sum)) +
          contingency_nm * log_outer)
    return mi.sum()
Ejemplo n.º 6
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def joint_entropy(X, Y):
    N = float(len(X))
    contingency = contingency_matrix(X, Y, sparse=True)
    nzx, nzy, Nall = sp.find(contingency)
    pAll = Nall / N
    S = -np.sum(pAll * np.log2(pAll))
    var = np.var(-np.log2(pAll))
    return S, var
Ejemplo n.º 7
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def clustering_accuracy(labels_true, labels_pred):
    """Compute clustering accuracy."""
    from sklearn.metrics.cluster import supervised
    from scipy.optimize import linear_sum_assignment
    labels_true, labels_pred = supervised.check_clusterings(labels_true, labels_pred)
    value = supervised.contingency_matrix(labels_true, labels_pred)
    [r, c] = linear_sum_assignment(-value)
    return value[r, c].sum() / len(labels_true)
Ejemplo n.º 8
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def est_joint_entropy(labels_true, labels_pred):

    N = float(len(labels_true))
    contingency = contingency_matrix(labels_true, labels_pred, sparse=True)
    nzx, nzy, Nall = sp.find(contingency)

    pAll = np.array([Ni * scipy.special.psi(Ni) for Ni in Nall if Ni > 0])
    S_hat = np.log2(N) - 1 / N * np.sum(pAll)
    return S_hat, np.var(1. / N * pAll)
Ejemplo n.º 9
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def est_joint_entropy(X, Y):

    N = float(len(X))
    contingency = contingency_matrix(X, Y, sparse=True)
    nzx, nzy, Nall = sp.find(contingency)

    pAll = np.array([Ni * scipy.special.psi(Ni) for Ni in Nall if Ni > 0])
    S_hat = np.log2(N) - 1 / N * np.sum(pAll)
    var = np.var(scipy.special.psi(np.array(Nall, dtype="float32")))
    return S_hat, var
Ejemplo n.º 10
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def get_fpr(y_true, y_pred):
    n_samples = np.shape(y_true)[0]
    c = contingency_matrix(y_true, y_pred, sparse=True)
    tk = np.dot(c.data, np.transpose(c.data)) - n_samples  # TP
    pk = np.sum(np.asarray(c.sum(axis=0)).ravel()**2) - n_samples  # TP+FP
    qk = np.sum(np.asarray(c.sum(axis=1)).ravel()**2) - n_samples  # TP+FN
    precision = 1. * tk / pk if tk != 0. else 0.
    recall = 1. * tk / qk if tk != 0. else 0.
    f = 2 * precision * recall / (precision + recall) if (precision +
                                                          recall) != 0. else 0.
    return f, precision, recall
def normalized_mutual_info_score(labels_true, labels_pred):
    labels_true, labels_pred = check_clusterings(labels_true, labels_pred)
    classes = np.unique(labels_true)
    clusters = np.unique(labels_pred)
    if (classes.shape[0] == clusters.shape[0] == 1
            or classes.shape[0] == clusters.shape[0] == 0):
        return 1.0
    contingency = contingency_matrix(labels_true, labels_pred, sparse=True)
    contingency = contingency.astype(np.float64)
    mi = mutual_info_score(labels_true, labels_pred, contingency=contingency)
    h_true, h_pred = entropy(labels_true), entropy(labels_pred)
    nmi = mi / max(np.sqrt(h_true * h_pred), 1e-10)
    return nmi
def adjusted_mutual_info_score(labels_true, labels_pred):
    labels_true, labels_pred = check_clusterings(labels_true, labels_pred)
    n_samples = labels_true.shape[0]
    classes = np.unique(labels_true)
    clusters = np.unique(labels_pred)
    if (classes.shape[0] == clusters.shape[0] == 1
            or classes.shape[0] == clusters.shape[0] == 0):
        return 1.0
    contingency = contingency_matrix(labels_true, labels_pred, sparse=True)
    contingency = contingency.astype(np.float64)
    # Calculate the MI for the two clusterings
    mi = mutual_info_score(labels_true, labels_pred, contingency=contingency)
    # Calculate the expected value for the mutual information
    emi = expected_mutual_information(contingency, n_samples)
    # Calculate entropy for each labeling
    h_true, h_pred = entropy(labels_true), entropy(labels_pred)
    ami = (mi - emi) / (max(h_true, h_pred) - emi)
    return ami
Ejemplo n.º 13
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def mutual_info_p(a, b, average_method="arithmetic", normalize=False):
    """ Fast mutual information calculation based upon sklearn,
    but with estimation of uncertainty from Lin & Tegmark 2016
    """
    # contingency matrix of a * b
    contingency = contingency_matrix(a, b, sparse=True)
    nzx, nzy, Nall = sp.find(contingency)
    N = len(a)
    # entropy of a
    Na = np.ravel(contingency.sum(axis=0))
    S_a, var_a = entropyp(Na / np.sum(Na))

    # entropy of b
    Nb = np.ravel(contingency.sum(axis=1))
    S_b, var_b = entropyp(Nb / np.sum(Nb))

    # joint entropy
    S_ab, var_ab = entropyp(Nall / N)

    # mutual information
    MI = S_a + S_b - S_ab

    # uncertainty and variance of MI
    MI_var = var_a + var_b + var_ab

    # normalization
    if normalize:
        # expected mutual information
        emi = expected_mutual_information(contingency, N)
        # normalization
        normalizer = _generalized_average(S_a, S_b, average_method)
        denominator = normalizer - emi
        if denominator < 0:
            denominator = min(denominator, -np.finfo("float64").eps)
        else:
            denominator = max(denominator, np.finfo("float64").eps)

        MI = (MI - emi) / denominator
        # this breaks MI_var - we would need to account for EMI
        MI_var = MI_var / denominator

    uncertainty = np.sqrt((MI_var) / len(a))

    return MI, uncertainty
Ejemplo n.º 14
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def adjusted_mutual_information(labels_true, labels_pred, n_jobs = -1, emi_method="parallel", use_cython=True,
                               average_method='arithmetic'):
    """Adjusted Mutual Information.
    Adjusted Mutual Information (AMI) is an adjustment of the Mutual
    Information (MI) score to account for chance. It accounts for the fact that
    the MI is generally higher for two clusterings with a larger number of
    clusters, regardless of whether there is actually more information shared.
    For two clusterings :math:`U` and :math:`V`, the AMI is given as::
        AMI(U, V) = [MI(U, V) - E(MI(U, V))] / [avg(H(U), H(V)) - E(MI(U, V))]
    
    """
    n_samples = labels_true.shape[0]
    classes = np.unique(labels_true)
    clusters = np.unique(labels_pred)
    # Special limit cases: no clustering since the data is not split.
    # This is a perfect match hence return 1.0.
    if (classes.shape[0] == clusters.shape[0] == 1 or
            classes.shape[0] == clusters.shape[0] == 0):
        return 1.0
    contingency = contingency_matrix(labels_true, labels_pred, sparse=True)
    contingency = contingency.astype(np.float64,
                                     **_astype_copy_false(contingency))
    # Calculate the MI for the two clusterings
    mi = mutual_info_score(labels_true, labels_pred,
                           contingency=contingency)
    # Calculate the expected value for the mutual information
    if emi_method == "parallel":
        emi = emi_parallel(contingency, n_samples, use_cython = use_cython, n_jobs=n_jobs)
    else:
        emi = expected_mutual_information(contingency, n_samples)
    # Calculate entropy for each labeling
    h_true, h_pred = entropy(labels_true), entropy(labels_pred)
    normalizer = _generalized_average(h_true, h_pred, average_method)
    denominator = normalizer - emi
    # Avoid 0.0 / 0.0 when expectation equals maximum, i.e a perfect match.
    # normalizer should always be >= emi, but because of floating-point
    # representation, sometimes emi is slightly larger. Correct this
    # by preserving the sign.
    if denominator < 0:
        denominator = min(denominator, -np.finfo('float64').eps)
    else:
        denominator = max(denominator, np.finfo('float64').eps)
    ami = (mi - emi) / denominator
    return ami, emi
Ejemplo n.º 15
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def clustering_accuracy(labels_true, labels_pred):
    """Clustering Accuracy between two clusterings.
    Clustering Accuracy is a measure of the similarity between two labels of
    the same data. Assume that both labels_true and labels_pred contain n 
    distinct labels. Clustering Accuracy is the maximum accuracy over all
    possible permutations of the labels, i.e.
    \max_{\sigma} \sum_i labels_true[i] == \sigma(labels_pred[i])
    where \sigma is a mapping from the set of unique labels of labels_pred to
    the set of unique labels of labels_true. Clustering accuracy is one if 
    and only if there is a permutation of the labels such that there is an
    exact match
    This metric is independent of the absolute values of the labels:
    a permutation of the class or cluster label values won't change the
    score value in any way.
    This metric is furthermore symmetric: switching ``label_true`` with
    ``label_pred`` will return the same score value. This can be useful to
    measure the agreement of two independent label assignments strategies
    on the same dataset when the real ground truth is not known.
    
    Parameters
    ----------
    labels_true : int array, shape = [n_samples]
    	A clustering of the data into disjoint subsets.
    labels_pred : array, shape = [n_samples]
    	A clustering of the data into disjoint subsets.
    
    Returns
    -------
    accuracy : float
       return clustering accuracy in the range of [0, 1]
    """
    labels_true, labels_pred = supervised.check_clusterings(
        labels_true, labels_pred)
    # value = supervised.contingency_matrix(labels_true, labels_pred, sparse=False)
    value = supervised.contingency_matrix(labels_true, labels_pred)
    [r, c] = linear_sum_assignment(-value)
    return value[r, c].sum() / len(labels_true)
Ejemplo n.º 16
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def folkes_mallow_score(labels_true, labels_pred):
    """
    Folkes&Mallow score  computed according to:

    Ceccarelli, M. & Maratea, A. A "Fuzzy Extension of Some Classical Concordance Measures and an Efficient Algorithm
    for Their Computation" Knowledge-Based Intelligent Information and Engineering Systems,
    Springer Berlin Heidelberg, 2008, 5179, 755-763

    :param labels_true:
    :param labels_pred:
    :return:
    """
    labels_true, labels_pred = check_clusterings(labels_true, labels_pred)
    n_samples = labels_true.shape[0]
    contingency = contingency_matrix(labels_true, labels_pred)

    cc = np.sum(contingency * contingency)
    N11 = (cc - n_samples)
    c1 = contingency.sum(axis=1)
    N01 = np.sum(c1 * c1) - cc
    c2 = contingency.sum(axis=0)
    N10 = np.sum(c2 * c2) - cc

    return (N11 * 1.0) / np.sqrt((N11 + N01) * (N11 + N10))
Ejemplo n.º 17
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def folkes_mallow_score(labels_true, labels_pred):
    """
    Folkes&Mallow score  computed according to:

    Ceccarelli, M. & Maratea, A. A "Fuzzy Extension of Some Classical Concordance Measures and an Efficient Algorithm
    for Their Computation" Knowledge-Based Intelligent Information and Engineering Systems,
    Springer Berlin Heidelberg, 2008, 5179, 755-763

    :param labels_true:
    :param labels_pred:
    :return:
    """
    labels_true, labels_pred = check_clusterings(labels_true, labels_pred)
    n_samples = labels_true.shape[0]
    contingency = contingency_matrix(labels_true, labels_pred)

    cc = np.sum(contingency * contingency)
    N11 = (cc - n_samples)
    c1 = contingency.sum(axis=1)
    N01 = np.sum(c1 * c1) - cc
    c2 = contingency.sum(axis=0)
    N10 = np.sum(c2 * c2) - cc

    return (N11*1.0)/np.sqrt((N11+N01)*(N11+N10))
Ejemplo n.º 18
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def mutual_info_score(labels_true, labels_pred, contingency=None):
    """Mutual Information between two clusterings.
    The Mutual Information is a measure of the similarity between two labels of
    the same data. Where :math:`|U_i|` is the number of the samples
    in cluster :math:`U_i` and :math:`|V_j|` is the number of the
    samples in cluster :math:`V_j`, the Mutual Information
    between clusterings :math:`U` and :math:`V` is given as:
    .. math::
        MI(U,V)=\sum_{i=1}^|U| \sum_{j=1}^|V| \\frac{|U_i\cap V_j|}{N}
        \log2\\frac{N|U_i \cap V_j|}{|U_i||V_j|}
    This metric is independent of the absolute values of the labels:
    a permutation of the class or cluster label values won't change the
    score value in any way.
    This metric is furthermore symmetric: switching ``label_true`` with
    ``label_pred`` will return the same score value. This can be useful to
    measure the agreement of two independent label assignments strategies
    on the same dataset when the real ground truth is not known.
    Read more in the :ref:`User Guide <mutual_info_score>`.
    Parameters
    ----------
    labels_true : int array, shape = [n_samples]
        A clustering of the data into disjoint subsets.
    labels_pred : array, shape = [n_samples]
        A clustering of the data into disjoint subsets.
    contingency : {None, array, sparse matrix},
                  shape = [n_classes_true, n_classes_pred]
        A contingency matrix given by the :func:`contingency_matrix` function.
        If value is ``None``, it will be computed, otherwise the given value is
        used, with ``labels_true`` and ``labels_pred`` ignored.
    Returns
    -------
    mi : float
       Mutual information, a non-negative value
    See also
    --------
    adjusted_mutual_info_score: Adjusted against chance Mutual Information
    normalized_mutual_info_score: Normalized Mutual Information
    """
    if contingency is None:
        labels_true, labels_pred = check_clusterings(labels_true, labels_pred)
        contingency = contingency_matrix(labels_true, labels_pred, sparse=True)
    else:
        contingency = check_array(contingency,
                                  accept_sparse=['csr', 'csc', 'coo'],
                                  dtype=[int, np.int32, np.int64])

    if isinstance(contingency, np.ndarray):
        # For an array
        nzx, nzy = np.nonzero(contingency)
        nz_val = contingency[nzx, nzy]
    elif sp.issparse(contingency):
        # For a sparse matrix
        nzx, nzy, nz_val = sp.find(contingency)
    else:
        raise ValueError("Unsupported type for 'contingency': %s" %
                         type(contingency))

    contingency_sum = contingency.sum()
    pi = np.ravel(contingency.sum(axis=1))
    pj = np.ravel(contingency.sum(axis=0))
    log2_contingency_nm = np.log2(nz_val)
    contingency_nm = nz_val / contingency_sum
    # Don't need to calculate the full outer product, just for non-zeroes
    outer = pi.take(nzx) * pj.take(nzy)
    log2_outer = -np.log2(outer) + log2(pi.sum()) + log2(pj.sum())
    mi = (contingency_nm * (log2_contingency_nm - log2(contingency_sum)) +
          contingency_nm * log2_outer)
    return mi.sum()
Ejemplo n.º 19
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def normalized_mutual_info_score(labels_true, labels_pred):
    """Normalized Mutual Information between two clusterings.
    Normalized Mutual Information (NMI) is an normalization of the Mutual
    Information (MI) score to scale the results between 0 (no mutual
    information) and 1 (perfect correlation). In this function, mutual
    information is normalized by ``sqrt(H(labels_true) * H(labels_pred))``
    This measure is not adjusted for chance. Therefore
    :func:`adjusted_mustual_info_score` might be preferred.
    This metric is independent of the absolute values of the labels:
    a permutation of the class or cluster label values won't change the
    score value in any way.
    This metric is furthermore symmetric: switching ``label_true`` with
    ``label_pred`` will return the same score value. This can be useful to
    measure the agreement of two independent label assignments strategies
    on the same dataset when the real ground truth is not known.
    Read more in the :ref:`User Guide <mutual_info_score>`.
    Parameters
    ----------
    labels_true : int array, shape = [n_samples]
        A clustering of the data into disjoint subsets.
    labels_pred : array, shape = [n_samples]
        A clustering of the data into disjoint subsets.
    Returns
    -------
    nmi : float
       score between 0.0 and 1.0. 1.0 stands for perfectly complete labeling
    See also
    --------
    adjusted_rand_score: Adjusted Rand Index
    adjusted_mutual_info_score: Adjusted Mutual Information (adjusted
        against chance)
    Examples
    --------
    Perfect labelings are both homogeneous and complete, hence have
    score 1.0::
      >>> from sklearn.metrics.cluster import normalized_mutual_info_score
      >>> normalized_mutual_info_score([0, 0, 1, 1], [0, 0, 1, 1])
      1.0
      >>> normalized_mutual_info_score([0, 0, 1, 1], [1, 1, 0, 0])
      1.0
    If classes members are completely split across different clusters,
    the assignment is totally in-complete, hence the NMI is null::
      >>> normalized_mutual_info_score([0, 0, 0, 0], [0, 1, 2, 3])
      0.0
    """
    labels_true, labels_pred = check_clusterings(labels_true, labels_pred)
    classes = np.unique(labels_true)
    clusters = np.unique(labels_pred)
    # Special limit cases: no clustering since the data is not split.
    # This is a perfect match hence return 1.0.
    if (classes.shape[0] == clusters.shape[0] == 1
            or classes.shape[0] == clusters.shape[0] == 0):
        return 1.0
    contingency = contingency_matrix(labels_true, labels_pred, sparse=True)
    contingency = contingency.astype(np.float64)
    # Calculate the MI for the two clusterings
    mi = mutual_info_score(labels_true, labels_pred, contingency=contingency)
    # Calculate the expected value for the mutual information
    # Calculate entropy for each labeling
    h_true, h_pred = entropy(labels_true), entropy(labels_pred)
    nmi = mi / max(np.sqrt(h_true * h_pred), 1e-10)
    return nmi
Ejemplo n.º 20
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def ari_ci(clusters, trueclusters, alpha=0.05):
    '''
    
    Steinley, Douglas, Michael J. Brusco, and Lawrence Hubert. "The variance of the adjusted Rand index." 
    Psychological methods 21.2 (2016): 261.
    
    Parameters
    ----------
    clusters : array, shape = [n_samples]
        Cluster labels to evaluate
    trueclusters : int array, shape = [n_samples]
        Ground truth class labels to be used as a reference
    alpha : float
        Alpha level for the normal approximation
    Returns
    -------
    ari : float
        Adjusted Rand Index between -1.0 and 1.0. 
    ari_variance : float
        variance of the ARI
    lowerci : float 
        CI lower limit 
    upperci : float
        CI upper limit
    
    '''
    ct = contingency_matrix(clusters, trueclusters).astype(np.float)
    N = ct.sum()

    # precompute some vars
    ncomb = _comb2(N)
    ctsqsum = (ct**2).sum()
    rssq = sum(ct.sum(1)**2)  # row sums sq
    cssq = sum(ct.sum(0)**2)  # col sums sq

    # use same var names as in Steinley et al
    a = (ctsqsum - N) / 2.0
    b = (rssq - ctsqsum) / 2.0
    c = (cssq - ctsqsum) / 2.0  # col sums sq
    d = (ctsqsum + N**2 - rssq - cssq) / 2.0
    e = 2.0 * rssq - (N + 1.0) * N
    f = 2.0 * cssq - (N + 1.0) * N
    g = 4.0 * sum(ct.sum(1)**3) - 4 * (N + 1.0) * rssq + (N + 1.0)**2 * N
    h = N * (N - 1.0)
    i = 4.0 * sum(ct.sum(0)**3) - 4.0 * (N + 1.0) * cssq + (N + 1.0)**2 * N

    var_aplusd = 1.0/16.0 * (2.0 * N * (N - 1.0) - ((e * f) / (N * (N - 1.0)))**2 +  \
                 (4.0 * (g - h) * (i - h)) / (N * (N - 1.0) * (N - 2.0))) +  \
                 1.0/16.0 * (((e**2 - 4 * g + 2 * h) * (f**2 - 4.0 * i + 2.0 * h)) /  \
                  (N * (N - 1.0) * (N - 2.0) * (N - 3.0)))

    ari_variance = (ncomb**2 * var_aplusd) / ((ncomb**2 -
                                               ((a + b) * (a + c) + (b + d) *
                                                (c + d)))**2)
    ari_std = np.sqrt(ari_variance)

    sum_comb_c = sum(_comb2(n_c) for n_c in np.ravel(ct.sum(axis=1)))
    sum_comb_k = sum(_comb2(n_k) for n_k in np.ravel(ct.sum(axis=0)))
    sum_comb = sum(_comb2(n_ij) for n_ij in np.ravel(ct))

    prod_comb = (sum_comb_c * sum_comb_k) / ncomb
    mean_comb = (sum_comb_k + sum_comb_c) / 2.

    #compute ari
    ari = (sum_comb - prod_comb) / (mean_comb - prod_comb)
    #compute CI
    qnrm = norm.ppf(1.0 - alpha / 2.0)
    lowerci = ari - qnrm * ari_std
    upperci = ari + qnrm * ari_std

    return ari, ari_variance, lowerci, upperci
Ejemplo n.º 21
0
print(fea_hog.transpose().shape)

#test_gamma = [.5,.55,.6,.65,.7,.75,.8,.85,.9,.95,1]
#test = [1,2,3,4,5,6,7,8,9,10]

# for x in test:
gauss_mix = GaussianMixture(n_components=5).fit(fea_hog.transpose())

#print(spec_clust.get_params())

labels_pred = np.array(gauss_mix.labels_)

#print(labels_pred.shape)

labels, labels_pred = supervised.check_clusterings(labels, labels_pred)
# labels_true : int array with ground truth labels, shape = [n_samples]
# labels_pred : int array with estimated labels, shape = [n_samples]
value = supervised.contingency_matrix(labels, labels_pred)
# value : array of shape [n, n] whose (i, j)-th entry is the number of samples in true class i and in predicted class j
[r, c] = linear_sum_assignment(-value)
accr = value[r, c].sum() / len(labels)

print('n_neighbors: ' + str(x) + ' accr: ' + str(accr))

# for x in range(0,20):
#     print(kmeans.labels_[x])

# for x in range(0,10):
#     print(data['fea_hog_train'][x])