Python distance.squareform方法代码示例

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def kernel_matrix(svm_model, original_X):

        if (svm_model.svm_kernel == 'polynomial_kernel' or svm_model.svm_kernel == 'soft_polynomial_kernel'):
            K = (svm_model.zeta + svm_model.gamma * np.dot(original_X, original_X.T)) ** svm_model.Q
        elif (svm_model.svm_kernel == 'gaussian_kernel' or svm_model.svm_kernel == 'soft_gaussian_kernel'):
            pairwise_dists = squareform(pdist(original_X, 'euclidean'))
            K = np.exp(-svm_model.gamma * (pairwise_dists ** 2))

        '''
        K = np.zeros((svm_model.data_num, svm_model.data_num))

        for i in range(svm_model.data_num):
            for j in range(svm_model.data_num):
                if (svm_model.svm_kernel == 'polynomial_kernel' or svm_model.svm_kernel == 'soft_polynomial_kernel'):
                    K[i, j] = Kernel.polynomial_kernel(svm_model, original_X[i], original_X[j])
                elif (svm_model.svm_kernel == 'gaussian_kernel' or svm_model.svm_kernel == 'soft_gaussian_kernel'):
                    K[i, j] = Kernel.gaussian_kernel(svm_model, original_X[i], original_X[j])
        '''

        return K 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def k_nearest_neighbor(self, sequence):
        # Calculate dist_matrix
        dist_array = pdist(sequence)
        dist_matrix = squareform(dist_array)
        # Construct tour
        new_sequence = [sequence[0]]
        current_city = 0
        visited_cities = [0]
        for i in range(1,len(sequence)):
            j = np.random.randint(0,min(len(sequence)-i,self.kNN))
            next_city = [index for index in dist_matrix[current_city].argsort() if index not in visited_cities][j]
            visited_cities.append(next_city)
            new_sequence.append(sequence[next_city])
            current_city = next_city
        return np.asarray(new_sequence)


    # Generate random TSP-TW instance 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def coords2sort_order(a2c):
  """ Delivers a list of atom indices which generates a near-diagonal overlap for a given set of atom coordinates """
  na  = a2c.shape[0]
  aa2d = squareform(pdist(a2c))
  mxd = np.amax(aa2d)+1.0
  a = 0
  lsa = []
  for ia in range(na):
    lsa.append(a)
    asrt = np.argsort(aa2d[a])
    for ja in range(1,na):
      b = asrt[ja]
      if b not in lsa: break
    aa2d[a,b] = aa2d[b,a] = mxd
    a = b
  return np.array(lsa) 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def vote(vec, tol):
    vec = np.sort(vec)
    n = np.arange(len(vec))[::-1]
    n = n[:, None] - n[None, :] + 1.0
    l = squareform(pdist(vec[:, None], 'minkowski', p=1) + 1e-9)

    invalid = (n < len(vec) * 0.4) | (l > tol)
    if (~invalid).sum() == 0 or len(vec) < tol:
        best_fit = np.median(vec)
        p_score = 0
    else:
        l[invalid] = 1e5
        n[invalid] = -1
        score = n
        max_idx = score.argmax()
        max_row = max_idx // len(vec)
        max_col = max_idx % len(vec)
        assert max_col > max_row
        best_fit = vec[max_row:max_col+1].mean()
        p_score = (max_col - max_row + 1) / len(vec)

    l1_score = np.abs(vec - best_fit).mean()

    return best_fit, p_score, l1_score 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def _get_sorted_db_keypoint_distances(self, N=None):
        """Use a minimum spanning tree heuristic to find the N largest gaps in the
        line constituted by the current decision boundary keypoints.
        """
        if N == None:
            N = self.n_interpolated_keypoints
        edges = minimum_spanning_tree(
            squareform(pdist(self.decision_boundary_points_2d))
        )
        edged = np.array(
            [
                euclidean(
                    self.decision_boundary_points_2d[u],
                    self.decision_boundary_points_2d[v],
                )
                for u, v in edges
            ]
        )
        gap_edge_idx = np.argsort(edged)[::-1][: int(N)]
        edges = edges[gap_edge_idx]
        gap_distances = np.square(edged[gap_edge_idx])
        gap_probability_scores = gap_distances / np.sum(gap_distances)
        return edges, gap_distances, gap_probability_scores 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def _execute_map(cls, ctx, op):
        inputs, device_id, xp = as_same_device(
            [ctx[inp.key] for inp in op.inputs], device=op.device, ret_extra=True)

        if len(inputs) == 2 and not inputs[1]:
            # check fail
            raise ValueError('Distance matrix X must be symmetric.')

        if xp is cp:  # pragma: no cover
            raise NotImplementedError('`squareform` does not support running on GPU yet')

        with device(device_id):
            x = inputs[0]
            if x.ndim == 1:
                cls._to_matrix(ctx, xp, x, op)
            else:
                cls._to_vector(ctx, xp, x, op) 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def execute(cls, ctx, op):
        if op.stage == OperandStage.map:
            cls._execute_map(ctx, op)
        elif op.stage == OperandStage.reduce:
            cls._execute_reduce(ctx, op)
        else:
            from scipy.spatial.distance import squareform

            (x,), device_id, xp = as_same_device(
                [ctx[inp.key] for inp in op.inputs], device=op.device, ret_extra=True)

            if xp is cp:  # pragma: no cover
                raise NotImplementedError('`squareform` does not support running on GPU yet')

            with device(device_id):
                ctx[op.outputs[0].key] = squareform(x, checks=op.checks) 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def _build_kernel(x, kernel, gamma=None):

    if kernel in {'pearson', 'spearman'}:
        if kernel == 'spearman':
            x = np.apply_along_axis(rankdata, 1, x)
        return np.corrcoef(x)

    if kernel in {'cosine', 'normalized_angle'}:
        x = 1 - squareform(pdist(x, metric='cosine'))
        if kernel == 'normalized_angle':
            x = 1 - np.arccos(x, x)/np.pi
        return x

    if kernel == 'gaussian':
        if gamma is None:
            gamma = 1 / x.shape[1]
        return rbf_kernel(x, gamma=gamma)

    if callable(kernel):
        return kernel(x)

    raise ValueError("Unknown kernel '{0}'.".format(kernel)) 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def test_euclidean_distances_sym(dtype, x_array_constr):
    # check that euclidean distances gives same result as scipy pdist
    # when only X is provided
    rng = np.random.RandomState(0)
    X = rng.random_sample((100, 10)).astype(dtype, copy=False)
    X[X < 0.8] = 0

    expected = squareform(pdist(X))

    X = x_array_constr(X)
    distances = euclidean_distances(X)

    # the default rtol=1e-7 is too close to the float32 precision
    # and fails due too rounding errors.
    assert_allclose(distances, expected, rtol=1e-6)
    assert distances.dtype == dtype 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def _run_answer_test(pos_input, pos_output, neighbors, grad_output,
                     verbose=False, perplexity=0.1, skip_num_points=0):
    distances = pairwise_distances(pos_input).astype(np.float32)
    args = distances, perplexity, verbose
    pos_output = pos_output.astype(np.float32)
    neighbors = neighbors.astype(np.int64, copy=False)
    pij_input = _joint_probabilities(*args)
    pij_input = squareform(pij_input).astype(np.float32)
    grad_bh = np.zeros(pos_output.shape, dtype=np.float32)

    from scipy.sparse import csr_matrix
    P = csr_matrix(pij_input)

    neighbors = P.indices.astype(np.int64)
    indptr = P.indptr.astype(np.int64)

    _barnes_hut_tsne.gradient(P.data, pos_output, neighbors, indptr,
                              grad_bh, 0.5, 2, 1, skip_num_points=0)
    assert_array_almost_equal(grad_bh, grad_output, decimal=4) 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def test_dbscan_similarity():
    # Tests the DBSCAN algorithm with a similarity array.
    # Parameters chosen specifically for this task.
    eps = 0.15
    min_samples = 10
    # Compute similarities
    D = distance.squareform(distance.pdist(X))
    D /= np.max(D)
    # Compute DBSCAN
    core_samples, labels = dbscan(D, metric="precomputed", eps=eps,
                                  min_samples=min_samples)
    # number of clusters, ignoring noise if present
    n_clusters_1 = len(set(labels)) - (1 if -1 in labels else 0)

    assert_equal(n_clusters_1, n_clusters)

    db = DBSCAN(metric="precomputed", eps=eps, min_samples=min_samples)
    labels = db.fit(D).labels_

    n_clusters_2 = len(set(labels)) - int(-1 in labels)
    assert_equal(n_clusters_2, n_clusters) 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def svgd_kernel(self, theta, h = -1):
        sq_dist = pdist(theta)
        pairwise_dists = squareform(sq_dist)**2
        if h < 0: # if h < 0, using median trick
            h = np.median(pairwise_dists)  
            h = np.sqrt(0.5 * h / np.log(theta.shape[0]+1))

        # compute the rbf kernel
        Kxy = np.exp( -pairwise_dists / h**2 / 2)

        dxkxy = -np.matmul(Kxy, theta)
        sumkxy = np.sum(Kxy, axis=1)
        for i in range(theta.shape[1]):
            dxkxy[:, i] = dxkxy[:,i] + np.multiply(theta[:,i],sumkxy)
        dxkxy = dxkxy / (h**2)
        return (Kxy, dxkxy) 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def svgd_kernel(self, h = -1):
        sq_dist = pdist(self.theta)
        pairwise_dists = squareform(sq_dist)**2
        if h < 0: # if h < 0, using median trick
            h = np.median(pairwise_dists)  
            h = np.sqrt(0.5 * h / np.log(self.theta.shape[0]+1))

        # compute the rbf kernel
        
        Kxy = np.exp( -pairwise_dists / h**2 / 2)

        dxkxy = -np.matmul(Kxy, self.theta)
        sumkxy = np.sum(Kxy, axis=1)
        for i in range(self.theta.shape[1]):
            dxkxy[:, i] = dxkxy[:,i] + np.multiply(self.theta[:,i],sumkxy)
        dxkxy = dxkxy / (h**2)
        return (Kxy, dxkxy) 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def correlated_timeseries(n_subjects, n_TRs, noise=0,
                          random_state=None):
    prng = np.random.RandomState(random_state)
    signal = prng.randn(n_TRs)
    correlated = True
    while correlated:
        uncorrelated = np.random.randn(n_TRs,
                                       n_subjects)[:, np.newaxis, :]
        unc_max = np.amax(squareform(np.corrcoef(
            uncorrelated[:, 0, :].T), checks=False))
        unc_mean = np.mean(squareform(np.corrcoef(
            uncorrelated[:, 0, :].T), checks=False))
        if unc_max < .3 and np.abs(unc_mean) < .001:
            correlated = False
    data = np.repeat(np.column_stack((signal, signal))[..., np.newaxis],
                     20, axis=2)
    data = np.concatenate((data, uncorrelated), axis=1)
    data = data + np.random.randn(n_TRs, 3, n_subjects) * noise
    return data


# Compute ISCs using different input types
# List of subjects with one voxel/ROI 

# 需要导入模块: from scipy.spatial import distance [as 别名]
# 或者: from scipy.spatial.distance import squareform [as 别名]
def calculate_edge_lengths(G, verbose=True):

    # Calculate the lengths of the edges

    if verbose:
        print('Calculating edge lengths...')

    x = np.matrix(G.nodes.data('x'))[:, 1]
    y = np.matrix(G.nodes.data('y'))[:, 1]

    node_coordinates = np.concatenate([x, y], axis=1)
    node_distances = squareform(pdist(node_coordinates, 'euclidean'))

    adjacency_matrix = np.array(nx.adjacency_matrix(G).todense())
    adjacency_matrix = adjacency_matrix.astype('float')
    adjacency_matrix[adjacency_matrix == 0] = np.nan

    edge_lengths = np.multiply(node_distances, adjacency_matrix)

    edge_attr_dict = {index: v for index, v in np.ndenumerate(edge_lengths) if ~np.isnan(v)}
    nx.set_edge_attributes(G, edge_attr_dict, 'length')

    return G