コード例 #1
0
def test_decomposed_local_centrality():
    # centralities on the original nodes within the decomposed network should equal non-decomposed workflow
    betas = np.array([-0.02, -0.01, -0.005, -0.0008, -0.0])
    distances = networks.distance_from_beta(betas)
    measure_keys = ('node_density',
                    'node_farness',
                    'node_cycles',
                    'node_harmonic',
                    'node_beta',
                    'segment_density',
                    'segment_harmonic',
                    'segment_beta',
                    'node_betweenness',
                    'node_betweenness_beta',
                    'segment_betweenness')
    # test a decomposed graph
    G = mock.mock_graph()
    G = graphs.nX_simple_geoms(G)
    node_uids, node_data, edge_data, node_edge_map = graphs.graph_maps_from_nX(G)  # generate node and edge maps
    measures_data = centrality.local_centrality(node_data,
                                                edge_data,
                                                node_edge_map,
                                                distances,
                                                betas,
                                                measure_keys,
                                                angular=False)
    G_decomposed = graphs.nX_decompose(G, 20)
    # generate node and edge maps
    node_uids, node_data, edge_data, node_edge_map = graphs.graph_maps_from_nX(G_decomposed)
    checks.check_network_maps(node_data, edge_data, node_edge_map)
    measures_data_decomposed = centrality.local_centrality(node_data,
                                                           edge_data,
                                                           node_edge_map,
                                                           distances,
                                                           betas,
                                                           measure_keys,
                                                           angular=False)
    # test harmonic closeness on original nodes for non-decomposed vs decomposed
    d_range = len(distances)
    m_range = len(measure_keys)
    assert measures_data.shape == (m_range, d_range, len(G))
    assert measures_data_decomposed.shape == (m_range, d_range, len(G_decomposed))
    original_node_idx = np.where(node_data[:, 3] == 0)
    # with increasing decomposition:
    # - node based measures will not match
    # - node based segment measures will match - these measure to the cut endpoints per thresholds
    # - betweenness based segment won't match - doesn't measure to cut endpoints
    for m_idx in range(m_range):
        print(m_idx)
        for d_idx in range(d_range):
            match = np.allclose(measures_data[m_idx][d_idx], measures_data_decomposed[m_idx][d_idx][original_node_idx],
                                atol=0.1, rtol=0)  # relax precision
            if not match:
                print('key', measure_keys[m_idx], 'dist:', distances[d_idx], 'match:', match)
            if m_idx in [5, 6, 7]:
                assert match
コード例 #2
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ファイル: networks.py プロジェクト: KalipheGTU/cityseer
 def compute_centrality(self,
                        measures: Union[list, tuple] = None,
                        angular: bool = False):
     # see centrality.local_centrality for integrity checks on closeness and betweenness keys
     # typos are caught below
     if not angular:
         heuristic = 'shortest (non-angular)'
         options = ('node_density', 'node_farness', 'node_cycles',
                    'node_harmonic', 'node_beta', 'segment_density',
                    'segment_harmonic', 'segment_beta', 'node_betweenness',
                    'node_betweenness_beta', 'segment_betweenness')
     else:
         heuristic = 'simplest (angular)'
         options = ('node_harmonic_angular', 'segment_harmonic_hybrid',
                    'node_betweenness_angular', 'segment_betweeness_hybrid')
     if measures is None:
         raise ValueError(f'Please select at least one measure to compute.')
     measure_keys = []
     for measure in measures:
         if measure not in options:
             raise ValueError(
                 f'Invalid network measure: {measure}. '
                 f'Must be one of {", ".join(options)} when using {heuristic} path heuristic.'
             )
         if measure in measure_keys:
             raise ValueError(
                 f'Please remove duplicate measure: {measure}.')
         measure_keys.append(measure)
     measure_keys = tuple(measure_keys)
     if not checks.quiet_mode:
         logger.info(
             f'Computing {", ".join(measure_keys)} centrality measures using {heuristic} path heuristic.'
         )
     measures_data = centrality.local_centrality(
         self._node_data,
         self._edge_data,
         self._node_edge_map,
         np.array(self._distances),
         np.array(self._betas),
         measure_keys,
         angular,
         suppress_progress=checks.quiet_mode)
     # write the results
     # writing metrics to dictionary will check for pre-existing
     # but writing sub-distances arrays will overwrite prior
     for measure_idx, measure_name in enumerate(measure_keys):
         if measure_name not in self.metrics['centrality']:
             self.metrics['centrality'][measure_name] = {}
         for d_idx, d_key in enumerate(self._distances):
             self.metrics['centrality'][measure_name][
                 d_key] = measures_data[measure_idx][d_idx]
コード例 #3
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 def wrapper_func():
     '''
     node density invokes aggregative workflow
     betweenness node invokes betweenness workflow
     segment density invokes segments workflow
     '''
     return centrality.local_centrality(node_data,
                                        edge_data,
                                        node_edge_map,
                                        distances,
                                        betas,
                                        ('node_density',  # 7.16s
                                         'node_betweenness',  # 8.08s - adds around 1s
                                         'segment_density',  # 11.2s - adds around 3s
                                         'segment_betweenness'
                                         ),
                                        angular=False,
                                        suppress_progress=True)
コード例 #4
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def test_compute_centrality():
    '''
    Underlying method also tested via test_networks.test_network_centralities
    '''
    G = mock.mock_graph()
    G = graphs.nX_simple_geoms(G)
    betas = np.array([-0.01, -0.005])
    distances = networks.distance_from_beta(betas)
    # generate data structures
    N = networks.Network_Layer_From_nX(G, distances)
    node_data = N._node_data
    edge_data = N._edge_data
    node_edge_map = N._node_edge_map
    # check measures against underlying method
    N = networks.Network_Layer_From_nX(G, distances)
    N.compute_centrality(measures=['node_density'])
    # test against underlying method
    measures_data = centrality.local_centrality(
        node_data,
        edge_data,
        node_edge_map,
        distances,
        betas,
        measure_keys=('node_density', ))
    for d_idx, d_key in enumerate(distances):
        assert np.allclose(N.metrics['centrality']['node_density'][d_key],
                           measures_data[0][d_idx])
    # also check the number of returned types for a few assortments of metrics
    measures = [
        'node_density', 'node_farness', 'node_cycles', 'node_harmonic',
        'segment_density', 'node_betweenness', 'segment_betweenness'
    ]
    np.random.shuffle(measures)  # in place
    # not necessary to do all labels, first few should do
    for min_idx in range(3):
        measure_keys = np.array(measures[min_idx:])
        N = networks.Network_Layer_From_nX(G, distances)
        N.compute_centrality(measures=measures)
        # test against underlying method
        measures_data = centrality.local_centrality(
            node_data,
            edge_data,
            node_edge_map,
            distances,
            betas,
            measure_keys=tuple(measure_keys))
        for m_idx, measure_name in enumerate(measure_keys):
            for d_idx, d_key in enumerate(distances):
                assert np.allclose(
                    N.metrics['centrality'][measure_name][d_key],
                    measures_data[m_idx][d_idx],
                    atol=0.001,
                    rtol=0)
    # check that angular gets passed through
    N_ang = networks.Network_Layer_From_nX(G, distances=[2000])
    N_ang.compute_centrality(measures=['node_harmonic_angular'], angular=True)
    N = networks.Network_Layer_From_nX(G, distances=[2000])
    N.compute_centrality(measures=['node_harmonic'], angular=False)
    assert not np.allclose(
        N_ang.metrics['centrality']['node_harmonic_angular'][2000],
        N.metrics['centrality']['node_harmonic'][2000],
        atol=0.001,
        rtol=0)
    assert not np.allclose(
        N_ang.metrics['centrality']['node_harmonic_angular'][2000],
        N.metrics['centrality']['node_harmonic'][2000],
        atol=0.001,
        rtol=0)
    # check that typos, duplicates, and mixed angular / non-angular are caught
    with pytest.raises(ValueError):
        N.compute_centrality(measures=['spelling_typo'])
    with pytest.raises(ValueError):
        N.compute_centrality(measures=['node_density', 'node_density'])
    with pytest.raises(ValueError):
        N.compute_centrality(
            measures=['harmonic_angle', 'node_harmonic_angular'])
コード例 #5
0
def test_local_centrality():
    '''
    Also tested indirectly via test_networks.test_compute_centrality

    Test centrality methods where possible against NetworkX - i.e. harmonic closeness and betweenness
    Note that NetworkX improved closeness is not the same as derivation used in this package
    NetworkX doesn't have a maximum distance cutoff, so run on the whole graph (low beta / high distance)
    '''
    # load the test graph
    G = mock.mock_graph()
    G = graphs.nX_simple_geoms(G)
    node_uids, node_data, edge_data, node_edge_map = graphs.graph_maps_from_nX(G)  # generate node and edge maps
    G_round_trip = graphs.nX_from_graph_maps(node_uids, node_data, edge_data, node_edge_map)
    # plots for debugging

    # needs a large enough beta so that distance thresholds aren't encountered
    betas = np.array([-0.02, -0.01, -0.005, -0.0008, -0.0])
    distances = networks.distance_from_beta(betas)
    # set the keys - add shuffling to be sure various orders work
    measure_keys = [
        'node_density',
        'node_farness',
        'node_cycles',
        'node_harmonic',
        'node_beta',
        'segment_density',
        'segment_harmonic',
        'segment_beta',
        'node_betweenness',
        'node_betweenness_beta',
        'segment_betweenness'
    ]
    np.random.shuffle(measure_keys)  # in place
    measure_keys = tuple(measure_keys)
    # generate the measures
    measures_data = centrality.local_centrality(node_data,
                                                edge_data,
                                                node_edge_map,
                                                distances,
                                                betas,
                                                measure_keys,
                                                angular=False)
    node_density = measures_data[measure_keys.index('node_density')]
    node_farness = measures_data[measure_keys.index('node_farness')]
    node_cycles = measures_data[measure_keys.index('node_cycles')]
    node_harmonic = measures_data[measure_keys.index('node_harmonic')]
    node_beta = measures_data[measure_keys.index('node_beta')]
    segment_density = measures_data[measure_keys.index('segment_density')]
    segment_harmonic = measures_data[measure_keys.index('segment_harmonic')]
    segment_beta = measures_data[measure_keys.index('segment_beta')]
    node_betweenness = measures_data[measure_keys.index('node_betweenness')]
    node_betweenness_beta = measures_data[measure_keys.index('node_betweenness_beta')]
    segment_betweenness = measures_data[measure_keys.index('segment_betweenness')]
    # post compute improved
    improved_closness = node_density / node_farness / node_density
    # angular keys
    measure_keys_angular = [
        'node_harmonic_angular',
        'segment_harmonic_hybrid',
        'node_betweenness_angular',
        'segment_betweeness_hybrid'
    ]
    np.random.shuffle(measure_keys_angular)  # in place
    measure_keys_angular = tuple(measure_keys_angular)
    # generate the angular measures
    measures_data_angular = centrality.local_centrality(node_data,
                                                        edge_data,
                                                        node_edge_map,
                                                        distances,
                                                        betas,
                                                        measure_keys_angular,
                                                        angular=True)
    node_harmonic_angular = measures_data_angular[measure_keys_angular.index('node_harmonic_angular')]
    segment_harmonic_hybrid = measures_data_angular[measure_keys_angular.index('segment_harmonic_hybrid')]
    node_betweenness_angular = measures_data_angular[measure_keys_angular.index('node_betweenness_angular')]
    segment_betweeness_hybrid = measures_data_angular[measure_keys_angular.index('segment_betweeness_hybrid')]

    # test node density
    # node density count doesn't include self-node
    # connected component == 48 == len(G) - 4
    # isolated looping component == 3
    # isolated edge == 1
    # isolated node == 0
    for n in node_density[4]:  # infinite distance - exceeds cutoff clashes
        assert n in [48, 3, 1, 0]
    # test harmonic closeness vs NetworkX
    nx_harm_cl = nx.harmonic_centrality(G_round_trip, distance='length')
    nx_harm_cl = np.array([v for v in nx_harm_cl.values()])
    assert np.allclose(nx_harm_cl, node_harmonic[4], atol=0.001, rtol=0)

    # test betweenness vs NetworkX
    # set endpoint counting to false and do not normalise
    nx_betw = nx.betweenness_centrality(G_round_trip, weight='length', endpoints=False, normalized=False)
    nx_betw = np.array([v for v in nx_betw.values()])
    # for some reason nx betweenness gives 0.5 instead of 1 for disconnected looping component (should be 1)
    # maybe two equidistant routes being divided through 2
    # nx betweenness gives 0.5 instead of 1 for all disconnected looping component nodes
    # nx presumably takes equidistant routes into account, in which case only the fraction is aggregated
    assert np.allclose(nx_betw[:52], node_betweenness[4][:52], atol=0.001, rtol=0)

    # test against various distances
    for d_idx in range(len(distances)):
        dist_cutoff = distances[d_idx]
        beta = betas[d_idx]

        # do the comparisons array-wise so that betweenness can be aggregated
        betw = np.full(G.number_of_nodes(), 0.0)
        betw_wt = np.full(G.number_of_nodes(), 0.0)
        dens = np.full(G.number_of_nodes(), 0.0)
        far_imp = np.full(G.number_of_nodes(), 0.0)
        far_dist = np.full(G.number_of_nodes(), 0.0)
        harmonic_cl = np.full(G.number_of_nodes(), 0.0)
        grav = np.full(G.number_of_nodes(), 0.0)
        cyc = np.full(G.number_of_nodes(), 0.0)

        for src_idx in range(len(G)):
            # get shortest path maps
            tree_map, tree_edges = centrality.shortest_path_tree(edge_data,
                                                                 node_edge_map,
                                                                 src_idx,
                                                                 dist_cutoff,
                                                                 angular=False)
            tree_preds = tree_map[:, 1]
            tree_dists = tree_map[:, 2]
            tree_imps = tree_map[:, 3]
            tree_cycles = tree_map[:, 4]
            for n_idx in G.nodes():
                # skip self nodes
                if n_idx == src_idx:
                    continue
                # get distance and impedance
                dist = tree_dists[n_idx]
                imp = tree_imps[n_idx]
                # continue if exceeds max
                if np.isinf(dist) or dist > dist_cutoff:
                    continue
                # aggregate values
                dens[src_idx] += 1
                far_imp[src_idx] += imp
                far_dist[src_idx] += dist
                harmonic_cl[src_idx] += 1 / imp
                grav[src_idx] += np.exp(beta * dist)
                # cycles
                if tree_cycles[n_idx]:
                    cyc[src_idx] += 1
                # BETWEENNESS
                # only process betweenness in one direction
                if n_idx < src_idx:
                    continue
                # betweenness - only counting truly between vertices, not starting and ending verts
                inter_idx = tree_preds[n_idx]
                # isolated nodes will have no predecessors
                if np.isnan(inter_idx):
                    continue
                inter_idx = np.int(inter_idx)
                while True:
                    # break out of while loop if the intermediary has reached the source node
                    if inter_idx == src_idx:
                        break
                    betw[inter_idx] += 1
                    betw_wt[inter_idx] += np.exp(beta * dist)
                    # follow
                    inter_idx = np.int(tree_preds[inter_idx])
        improved_cl = dens / far_dist / dens

        assert np.allclose(node_density[d_idx], dens, atol=0.001, rtol=0)
        assert np.allclose(node_farness[d_idx], far_dist, atol=0.01, rtol=0)  # relax precision
        assert np.allclose(node_cycles[d_idx], cyc, atol=0.001, rtol=0)
        assert np.allclose(node_harmonic[d_idx], harmonic_cl, atol=0.001, rtol=0)
        assert np.allclose(node_beta[d_idx], grav, atol=0.001, rtol=0)
        assert np.allclose(improved_closness[d_idx], improved_cl, equal_nan=True, atol=0.001, rtol=0)
        assert np.allclose(node_betweenness[d_idx], betw, atol=0.001, rtol=0)
        assert np.allclose(node_betweenness_beta[d_idx], betw_wt, atol=0.001, rtol=0)

        # TODO: are there possibly ways to test segment_density, harmonic_segment, segment_beta, segment_betweenness
        # for infinite distance, the segment density should match the sum of reachable segments
        length_sum = 0
        for s, e, d in G_round_trip.edges(data=True):
            length_sum += d['length']
        reachable_length_sum = length_sum - \
                               (G_round_trip[50][51]['length'] +
                                G_round_trip[52][53]['length'] +
                                G_round_trip[53][54]['length'] +
                                G_round_trip[54][55]['length'] +
                                G_round_trip[52][55]['length'])
        assert np.allclose(segment_density[-1][:49], reachable_length_sum, atol=0.01, rtol=0)  # relax precision

    # check that problematic keys are caught
    for angular, k in zip([False, True], ['node_harmonic', 'node_harmonic_angular']):
        # catch typos
        with pytest.raises(ValueError):
            centrality.local_centrality(node_data,
                                        edge_data,
                                        node_edge_map,
                                        distances,
                                        betas,
                                        ('typo_key',),
                                        angular=False)
        # catch duplicates
        with pytest.raises(ValueError):
            centrality.local_centrality(node_data,
                                        edge_data,
                                        node_edge_map,
                                        distances,
                                        betas,
                                        (k, k),
                                        angular=False)
        # catch mixed angular and non-angular keys
        with pytest.raises(ValueError):
            centrality.local_centrality(node_data,
                                        edge_data,
                                        node_edge_map,
                                        distances,
                                        betas,
                                        ('node_density', 'node_harmonic_angular'),
                                        angular=False)