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-rw-r--r--src/python/gudhi/clustering/__init__.py0
-rw-r--r--src/python/gudhi/clustering/_tomato.cc277
-rw-r--r--src/python/gudhi/clustering/tomato.py321
3 files changed, 598 insertions, 0 deletions
diff --git a/src/python/gudhi/clustering/__init__.py b/src/python/gudhi/clustering/__init__.py
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/src/python/gudhi/clustering/__init__.py
diff --git a/src/python/gudhi/clustering/_tomato.cc b/src/python/gudhi/clustering/_tomato.cc
new file mode 100644
index 00000000..a76a2c3a
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+++ b/src/python/gudhi/clustering/_tomato.cc
@@ -0,0 +1,277 @@
+/* This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
+ * See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
+ * Author(s): Marc Glisse
+ *
+ * Copyright (C) 2020 Inria
+ *
+ * Modification(s):
+ * - YYYY/MM Author: Description of the modification
+ */
+
+#include <boost/container/flat_map.hpp>
+#include <boost/pending/disjoint_sets.hpp>
+#include <boost/property_map/property_map.hpp>
+#include <boost/property_map/transform_value_property_map.hpp>
+#include <boost/property_map/vector_property_map.hpp>
+#include <boost/property_map/function_property_map.hpp>
+#include <boost/iterator/counting_iterator.hpp>
+#include <boost/range/irange.hpp>
+#include <boost/range/adaptor/transformed.hpp>
+#include <vector>
+#include <unordered_map>
+#include <pybind11/pybind11.h>
+#include <pybind11/numpy.h>
+#include <iostream>
+
+namespace py = pybind11;
+
+template <class T, class = std::enable_if_t<std::is_integral<T>::value>>
+int getint(int i) {
+ return i;
+}
+// Gcc-8 has a bug that breaks this version, fixed in gcc-9
+// template<class T, class=decltype(std::declval<T>().template cast<int>())>
+// int getint(T i){return i.template cast<int>();}
+template <class T>
+auto getint(T i) -> decltype(i.template cast<int>()) {
+ return i.template cast<int>();
+}
+
+// Raw clusters are clusters obtained through single-linkage, no merging.
+
+typedef int Point_index;
+typedef int Cluster_index;
+struct Merge {
+ Cluster_index first, second;
+ double persist;
+};
+
+template <class Neighbors, class Density, class Order, class ROrder>
+auto tomato(Point_index num_points, Neighbors const& neighbors, Density const& density, Order const& order,
+ ROrder const& rorder) {
+ // point index --> index of raw cluster it belongs to
+ std::vector<Cluster_index> raw_cluster;
+ raw_cluster.reserve(num_points);
+ // cluster index --> index of top point in the cluster
+ Cluster_index n_raw_clusters = 0; // current number of raw clusters seen
+ //
+ std::vector<Merge> merges;
+ struct Data {
+ Cluster_index parent;
+ int rank;
+ Point_index max;
+ }; // information on a cluster
+ std::vector<Data> ds_base;
+ // boost::vector_property_map does resize(size+1) for every new element, don't use it
+ auto ds_data =
+ boost::make_function_property_map<std::size_t>([&ds_base](std::size_t n) -> Data& { return ds_base[n]; });
+ auto ds_parent =
+ boost::make_transform_value_property_map([](auto& p) -> Cluster_index& { return p.parent; }, ds_data);
+ auto ds_rank = boost::make_transform_value_property_map([](auto& p) -> int& { return p.rank; }, ds_data);
+ boost::disjoint_sets<decltype(ds_rank), decltype(ds_parent)> ds(
+ ds_rank, ds_parent); // on the clusters, not directly the points
+ std::vector<std::array<double, 2>> persistence; // diagram (finite points)
+ boost::container::flat_map<Cluster_index, Cluster_index>
+ adj_clusters; // first: the merged cluster, second: the raw cluster
+ // we only care about the raw cluster, we could use a vector to store the second, store first into a set, and only
+ // insert in the vector if merged is absent from the set
+
+ for (Point_index i = 0; i < num_points; ++i) {
+ // auto&& ngb = neighbors[order[i]];
+ // TODO: have a specialization where we don't need python types and py::cast
+ // TODO: move py::cast and getint into Neighbors
+ py::object ngb = neighbors[py::cast(order[i])]; // auto&& also seems to work
+ adj_clusters.clear();
+ Point_index j = i; // highest neighbor
+ // for(Point_index k : ngb)
+ for (auto k_py : ngb) {
+ Point_index k = rorder[getint(k_py)];
+ if (k >= i || k < 0) // ???
+ continue;
+ if (k < j) j = k;
+ Cluster_index rk = raw_cluster[k];
+ adj_clusters.emplace(ds.find_set(rk), rk);
+ // does not insert if ck=ds.find_set(rk) already seen
+ // which rk we keep from those with the same ck is arbitrary
+ }
+ assert((Point_index)raw_cluster.size() == i);
+ if (i == j) { // local maximum -> new cluster
+ Cluster_index c = n_raw_clusters++;
+ ds_base.emplace_back(); // could be integrated in ds_data, but then we would check the size for every access
+ ds.make_set(c);
+ ds_base[c].max = i; // max
+ raw_cluster.push_back(c);
+ continue;
+ } else { // add i to the cluster of j
+ assert(j < i);
+ raw_cluster.push_back(raw_cluster[j]);
+ // FIXME: we are adding point i to the raw cluster of j, but that one might not be in adj_clusters, so we may
+ // merge clusters A and B through a point of C. It is strange, but I don't know if it can really cause problems.
+ // We could just not set j at all and use arbitrarily the first element of adj_clusters.
+ }
+ // possibly merge clusters
+ // we could sort, in case there are several merges, but that doesn't seem so useful
+ Cluster_index rj = raw_cluster[j];
+ Cluster_index cj = ds.find_set(rj);
+ Cluster_index orig_cj = cj;
+ for (auto ckk : adj_clusters) {
+ Cluster_index rk = ckk.second;
+ Cluster_index ck = ckk.first;
+ if (ck == orig_cj) continue;
+ assert(ck == ds.find_set(rk));
+ Point_index j = ds_base[cj].max;
+ Point_index k = ds_base[ck].max;
+ Point_index young = std::max(j, k);
+ Point_index old = std::min(j, k);
+ auto d_young = density[order[young]];
+ auto d_i = density[order[i]];
+ assert(d_young >= d_i);
+ // Always merge (the non-hierarchical algorithm would only conditionally merge here
+ persistence.push_back({d_young, d_i});
+ assert(ds.find_set(rj) != ds.find_set(rk));
+ ds.link(cj, ck);
+ cj = ds.find_set(cj);
+ ds_base[cj].max = old; // just one parent, no need for find_set
+ // record the raw clusters, we don't know what will have already been merged.
+ merges.push_back({rj, rk, d_young - d_i});
+ }
+ }
+ {
+ boost::counting_iterator<int> b(0), e(ds_base.size());
+ ds.compress_sets(b, e);
+ // Now we stop using find_sets and look at the parent directly
+ // rank is reused to rename clusters contiguously 0, 1, etc
+ }
+ // Maximum for each connected component
+ std::vector<double> max_cc;
+ for (Cluster_index i = 0; i < n_raw_clusters; ++i) {
+ if (ds_base[i].parent == i) max_cc.push_back(density[order[ds_base[i].max]]);
+ }
+ assert((Cluster_index)(merges.size() + max_cc.size()) == n_raw_clusters);
+
+ // TODO: create a "noise" cluster, merging all those not prominent enough?
+
+ // Replay the merges, in increasing order of prominence, to build the hierarchy
+ std::sort(merges.begin(), merges.end(), [](Merge const& a, Merge const& b) { return a.persist < b.persist; });
+ std::vector<std::array<Cluster_index, 2>> children;
+ children.reserve(merges.size());
+ {
+ struct Dat {
+ Cluster_index parent;
+ int rank;
+ Cluster_index name;
+ };
+ std::vector<Dat> ds_bas(2 * n_raw_clusters - 1);
+ Cluster_index i;
+ auto ds_dat =
+ boost::make_function_property_map<std::size_t>([&ds_bas](std::size_t n) -> Dat& { return ds_bas[n]; });
+ auto ds_par = boost::make_transform_value_property_map([](auto& p) -> Cluster_index& { return p.parent; }, ds_dat);
+ auto ds_ran = boost::make_transform_value_property_map([](auto& p) -> int& { return p.rank; }, ds_dat);
+ boost::disjoint_sets<decltype(ds_ran), decltype(ds_par)> ds(ds_ran, ds_par);
+ for (i = 0; i < n_raw_clusters; ++i) {
+ ds.make_set(i);
+ ds_bas[i].name = i;
+ }
+ for (Merge const& m : merges) {
+ Cluster_index j = ds.find_set(m.first);
+ Cluster_index k = ds.find_set(m.second);
+ assert(j != k);
+ children.push_back({ds_bas[j].name, ds_bas[k].name});
+ ds.make_set(i);
+ ds.link(i, j);
+ ds.link(i, k);
+ ds_bas[ds.find_set(i)].name = i;
+ ++i;
+ }
+ }
+
+ std::vector<Cluster_index> raw_cluster_ordered(num_points);
+ for (int i = 0; i < num_points; ++i) raw_cluster_ordered[i] = raw_cluster[rorder[i]];
+ // return raw_cluster, children, persistence
+ // TODO avoid copies: https://github.com/pybind/pybind11/issues/1042
+ return py::make_tuple(py::array(raw_cluster_ordered.size(), raw_cluster_ordered.data()),
+ py::array(children.size(), children.data()), py::array(persistence.size(), persistence.data()),
+ py::array(max_cc.size(), max_cc.data()));
+}
+
+auto merge(py::array_t<Cluster_index, py::array::c_style> children, Cluster_index n_leaves, Cluster_index n_final) {
+ if (n_final > n_leaves) {
+ std::cerr << "The number of clusters required " << n_final << " is larger than the number of mini-clusters " << n_leaves << '\n';
+ n_final = n_leaves; // or return something special and let Tomato use leaf_labels_?
+ }
+ py::buffer_info cbuf = children.request();
+ if ((cbuf.ndim != 2 || cbuf.shape[1] != 2) && (cbuf.ndim != 1 || cbuf.shape[0] != 0))
+ throw std::runtime_error("internal error: children have to be (n,2) or empty");
+ const int n_merges = cbuf.shape[0];
+ Cluster_index* d = (Cluster_index*)cbuf.ptr;
+ if (n_merges + n_final < n_leaves) {
+ std::cerr << "The number of clusters required " << n_final << " is smaller than the number of connected components " << n_leaves - n_merges << '\n';
+ n_final = n_leaves - n_merges;
+ }
+ struct Dat {
+ Cluster_index parent;
+ int rank;
+ int name;
+ };
+ std::vector<Dat> ds_bas(2 * n_leaves - 1);
+ auto ds_dat = boost::make_function_property_map<std::size_t>([&ds_bas](std::size_t n) -> Dat& { return ds_bas[n]; });
+ auto ds_par = boost::make_transform_value_property_map([](auto& p) -> Cluster_index& { return p.parent; }, ds_dat);
+ auto ds_ran = boost::make_transform_value_property_map([](auto& p) -> int& { return p.rank; }, ds_dat);
+ boost::disjoint_sets<decltype(ds_ran), decltype(ds_par)> ds(ds_ran, ds_par);
+ Cluster_index i;
+ for (i = 0; i < n_leaves; ++i) {
+ ds.make_set(i);
+ ds_bas[i].name = -1;
+ }
+ for (Cluster_index m = 0; m < n_leaves - n_final; ++m) {
+ Cluster_index j = ds.find_set(d[2 * m]);
+ Cluster_index k = ds.find_set(d[2 * m + 1]);
+ assert(j != k);
+ ds.make_set(i);
+ ds.link(i, j);
+ ds.link(i, k);
+ ++i;
+ }
+ Cluster_index next_cluster_name = 0;
+ std::vector<Cluster_index> ret;
+ ret.reserve(n_leaves);
+ for (Cluster_index j = 0; j < n_leaves; ++j) {
+ Cluster_index k = ds.find_set(j);
+ if (ds_bas[k].name == -1) ds_bas[k].name = next_cluster_name++;
+ ret.push_back(ds_bas[k].name);
+ }
+ return py::array(ret.size(), ret.data());
+}
+
+// TODO: Do a special version when ngb is a numpy array, where we can cast to int[k][n] ?
+// py::isinstance<py::array_t<std::int32_t>> (ou py::isinstance<py::array> et tester dtype) et flags&c_style
+// ou overload (en virant forcecast?)
+// aussi le faire au cas où on n'aurait pas un tableau, mais où chaque liste de voisins serait un tableau ?
+auto hierarchy(py::handle ngb, py::array_t<double, py::array::c_style | py::array::forcecast> density) {
+ // used to be py::iterable ngb, but that's inconvenient if it doesn't come pre-sorted
+ // use py::handle and check if [] (aka __getitem__) works? But then we need to build an object to pass it to []
+ // (I _think_ handle is ok and we don't need object here)
+ py::buffer_info wbuf = density.request();
+ if (wbuf.ndim != 1) throw std::runtime_error("density must be 1D");
+ const int n = wbuf.shape[0];
+ double* d = (double*)wbuf.ptr;
+ // Vector { 0, 1, ..., n-1 }
+ std::vector<Point_index> order(boost::counting_iterator<Point_index>(0), boost::counting_iterator<Point_index>(n));
+ // Permutation of the indices to get points in decreasing order of density
+ std::sort(std::begin(order), std::end(order), [=](Point_index i, Point_index j) { return d[i] > d[j]; });
+ // Inverse permutation
+ std::vector<Point_index> rorder(n);
+ for (Point_index i : boost::irange(0, n)) rorder[order[i]] = i;
+ // Used as:
+ // order[i] is the index of the point with i-th largest density
+ // rorder[i] is the rank of the i-th point in order of decreasing density
+ // TODO: put a wrapper on ngb and d so we don't need to pass (r)order (there is still the issue of reordering the
+ // output)
+ return tomato(n, ngb, d, order, rorder);
+}
+
+PYBIND11_MODULE(_tomato, m) {
+ m.doc() = "Internals of tomato clustering";
+ m.def("hierarchy", &hierarchy, "does the clustering");
+ m.def("merge", &merge, "merge clusters");
+}
diff --git a/src/python/gudhi/clustering/tomato.py b/src/python/gudhi/clustering/tomato.py
new file mode 100644
index 00000000..d0e9995c
--- /dev/null
+++ b/src/python/gudhi/clustering/tomato.py
@@ -0,0 +1,321 @@
+# This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
+# See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
+# Author(s): Marc Glisse
+#
+# Copyright (C) 2020 Inria
+#
+# Modification(s):
+# - YYYY/MM Author: Description of the modification
+
+import numpy
+from ..point_cloud.knn import KNearestNeighbors
+from ..point_cloud.dtm import DTMDensity
+from ._tomato import *
+
+# The fit/predict interface is not so well suited...
+
+
+class Tomato:
+ """
+ This clustering algorithm needs a neighborhood graph on the points, and an estimation of the density at each point.
+ A few possible graph constructions and density estimators are provided for convenience, but it is perfectly natural
+ to provide your own.
+
+ :Requires: `SciPy <installation.html#scipy>`_, `Scikit-learn <installation.html#scikit-learn>`_ or others
+ (see :class:`~gudhi.point_cloud.knn.KNearestNeighbors`) in function of the options.
+
+ Attributes
+ ----------
+ n_clusters_: int
+ The number of clusters. Writing to it automatically adjusts `labels_`.
+ merge_threshold_: float
+ minimum prominence of a cluster so it doesn't get merged. Writing to it automatically adjusts `labels_`.
+ n_leaves_: int
+ number of leaves (unstable clusters) in the hierarchical tree
+ leaf_labels_: ndarray of shape (n_samples,)
+ cluster labels for each point, at the very bottom of the hierarchy
+ labels_: ndarray of shape (n_samples,)
+ cluster labels for each point, after merging
+ diagram_: ndarray of shape (`n_leaves_`, 2)
+ persistence diagram (only the finite points)
+ max_weight_per_cc_: ndarray of shape (n_connected_components,)
+ maximum of the density function on each connected component. This corresponds to the abscissa of infinite
+ points in the diagram
+ children_: ndarray of shape (`n_leaves_`-n_connected_components, 2)
+ The children of each non-leaf node. Values less than `n_leaves_` correspond to leaves of the tree.
+ A node i greater than or equal to `n_leaves_` is a non-leaf node and has children children_[i - `n_leaves_`].
+ Alternatively at the i-th iteration, children[i][0] and children[i][1] are merged to form node `n_leaves_` + i
+ weights_: ndarray of shape (n_samples,)
+ weights of the points, as computed by the density estimator or provided by the user
+ params_: dict
+ Parameters like metric, etc
+ """
+
+ def __init__(
+ self,
+ graph_type="knn",
+ density_type="logDTM",
+ n_clusters=None,
+ merge_threshold=None,
+ # eliminate_threshold=None,
+ # eliminate_threshold (float): minimum max weight of a cluster so it doesn't get eliminated
+ **params
+ ):
+ """
+ Args:
+ graph_type (str): 'manual', 'knn' or 'radius'. Default is 'knn'.
+ density_type (str): 'manual', 'DTM', 'logDTM', 'KDE' or 'logKDE'. When you have many points,
+ 'KDE' and 'logKDE' tend to be slower. Default is 'logDTM'.
+ metric (str|Callable): metric used when calculating the distance between instances in a feature array.
+ Defaults to Minkowski of parameter p.
+ kde_params (dict): if density_type is 'KDE' or 'logKDE', additional parameters passed directly to
+ sklearn.neighbors.KernelDensity.
+ k (int): number of neighbors for a knn graph (including the vertex itself). Defaults to 10.
+ k_DTM (int): number of neighbors for the DTM density estimation (including the vertex itself).
+ Defaults to k.
+ r (float): size of a neighborhood if graph_type is 'radius'. Also used as default bandwidth in kde_params.
+ eps (float): (1+eps) approximation factor when computing distances (ignored in many cases).
+ n_clusters (int): number of clusters requested. Defaults to None, i.e. no merging occurs and we get
+ the maximal number of clusters.
+ merge_threshold (float): minimum prominence of a cluster so it doesn't get merged.
+ symmetrize_graph (bool): whether we should add edges to make the neighborhood graph symmetric.
+ This can be useful with k-NN for small k. Defaults to false.
+ p (float): norm L^p on input points. Defaults to 2.
+ q (float): order used to compute the distance to measure. Defaults to dim.
+ Beware that when the dimension is large, this can easily cause overflows.
+ dim (float): final exponent in DTM density estimation, representing the dimension. Defaults to the
+ dimension, or 2 when the dimension cannot be read from the input (metric is "precomputed").
+ n_jobs (int): Number of jobs to schedule for parallel processing on the CPU.
+ If -1 is given all processors are used. Default: 1.
+ params: extra parameters are passed to :class:`~gudhi.point_cloud.knn.KNearestNeighbors` and
+ :class:`~gudhi.point_cloud.dtm.DTMDensity`.
+ """
+ # Should metric='precomputed' mean input_type='distance_matrix'?
+ # Should we be able to pass metric='minkowski' (what None does currently)?
+ self.graph_type_ = graph_type
+ self.density_type_ = density_type
+ self.params_ = params
+ self.__n_clusters = n_clusters
+ self.__merge_threshold = merge_threshold
+ # self.eliminate_threshold_ = eliminate_threshold
+ if n_clusters and merge_threshold:
+ raise ValueError("Cannot specify both a merge threshold and a number of clusters")
+
+ def fit(self, X, y=None, weights=None):
+ """
+ Args:
+ X ((n,d)-array of float|(n,n)-array of float|Sequence[Iterable[int]]): coordinates of the points,
+ or distance matrix (full, not just a triangle) if metric is "precomputed", or list of neighbors
+ for each point (points are represented by their index, starting from 0) if graph_type is "manual".
+ The number of points is currently limited to about 2 billion.
+ weights (ndarray of shape (n_samples)): if density_type is 'manual', a density estimate at each point
+ y: Not used, present here for API consistency with scikit-learn by convention.
+ """
+ # TODO: First detect if this is a new call with the same data (only threshold changed?)
+ # TODO: less code duplication (subroutines?), less spaghetti, but don't compute neighbors twice if not needed. Clear error message for missing or contradictory parameters.
+ if weights is not None:
+ density_type = "manual"
+ else:
+ density_type = self.density_type_
+ if density_type == "manual":
+ raise ValueError("If density_type is 'manual', you must provide weights to fit()")
+
+ if self.graph_type_ == "manual":
+ self.neighbors_ = X
+ # FIXME: uniformize "message 'option'" vs 'message "option"'
+ assert density_type == "manual", 'If graph_type is "manual", density_type must be as well'
+ else:
+ metric = self.params_.get("metric", "minkowski")
+ if metric != "precomputed":
+ self.points_ = X
+
+ # Slight complication to avoid computing knn twice.
+ need_knn = 0
+ need_knn_ngb = False
+ need_knn_dist = False
+ if self.graph_type_ == "knn":
+ k_graph = self.params_.get("k", 10)
+ # If X has fewer than k points...
+ if k_graph > len(X):
+ k_graph = len(X)
+ need_knn = k_graph
+ need_knn_ngb = True
+ if self.density_type_ in ["DTM", "logDTM"]:
+ k = self.params_.get("k", 10)
+ k_DTM = self.params_.get("k_DTM", k)
+ # If X has fewer than k points...
+ if k_DTM > len(X):
+ k_DTM = len(X)
+ need_knn = max(need_knn, k_DTM)
+ need_knn_dist = True
+ # if we ask for more neighbors for the graph than the DTM, getting the distances is a slight waste,
+ # but it looks negligible
+ if need_knn > 0:
+ knn_args = dict(self.params_)
+ knn_args["k"] = need_knn
+ knn = KNearestNeighbors(return_index=need_knn_ngb, return_distance=need_knn_dist, **knn_args).fit_transform(
+ X
+ )
+ if need_knn_ngb:
+ if need_knn_dist:
+ self.neighbors_ = knn[0][:, 0:k_graph]
+ knn_dist = knn[1]
+ else:
+ self.neighbors_ = knn
+ elif need_knn_dist:
+ knn_dist = knn
+ if self.density_type_ in ["DTM", "logDTM"]:
+ dim = self.params_.get("dim")
+ if dim is None:
+ dim = len(X[0]) if metric != "precomputed" else 2
+ q = self.params_.get("q", dim)
+ weights = DTMDensity(k=k_DTM, metric="neighbors", dim=dim, q=q).fit_transform(knn_dist)
+ if self.density_type_ == "logDTM":
+ weights = numpy.log(weights)
+
+ if self.graph_type_ == "radius":
+ if metric in ["minkowski", "euclidean", "manhattan", "chebyshev"]:
+ from scipy.spatial import cKDTree
+
+ tree = cKDTree(X)
+ # TODO: handle "l1" and "l2" aliases?
+ p = self.params_.get("p")
+ if metric == "euclidean":
+ assert p is None or p == 2, "p=" + str(p) + " is not consistent with metric='euclidean'"
+ p = 2
+ elif metric == "manhattan":
+ assert p is None or p == 1, "p=" + str(p) + " is not consistent with metric='manhattan'"
+ p = 1
+ elif metric == "chebyshev":
+ assert p is None or p == numpy.inf, "p=" + str(p) + " is not consistent with metric='chebyshev'"
+ p = numpy.inf
+ elif p is None:
+ p = 2 # the default
+ eps = self.params_.get("eps", 0)
+ self.neighbors_ = tree.query_ball_tree(tree, r=self.params_["r"], p=p, eps=eps)
+
+ # TODO: sklearn's NearestNeighbors.radius_neighbors can handle more metrics efficiently via its BallTree
+ # (don't bother with the _graph variant, it just calls radius_neighbors).
+ elif metric != "precomputed":
+ from sklearn.metrics import pairwise_distances
+
+ X = pairwise_distances(X, metric=metric, n_jobs=self.params_.get("n_jobs"))
+ metric = "precomputed"
+
+ if metric == "precomputed":
+ # TODO: parallelize? May not be worth it.
+ X = numpy.asarray(X)
+ r = self.params_["r"]
+ self.neighbors_ = [numpy.flatnonzero(l <= r) for l in X]
+
+ if self.density_type_ in {"KDE", "logKDE"}:
+ # Slow...
+ assert (
+ self.graph_type_ != "manual" and metric != "precomputed"
+ ), "Scikit-learn's KernelDensity requires point coordinates"
+ kde_params = dict(self.params_.get("kde_params", dict()))
+ kde_params.setdefault("metric", metric)
+ r = self.params_.get("r")
+ if r is not None:
+ kde_params.setdefault("bandwidth", r)
+ # Should we default rtol to eps?
+ from sklearn.neighbors import KernelDensity
+
+ weights = KernelDensity(**kde_params).fit(self.points_).score_samples(self.points_)
+ if self.density_type_ == "KDE":
+ weights = numpy.exp(weights)
+
+ # TODO: do it at the C++ level and/or in parallel if this is too slow?
+ if self.params_.get("symmetrize_graph"):
+ self.neighbors_ = [set(line) for line in self.neighbors_]
+ for i, line in enumerate(self.neighbors_):
+ line.discard(i)
+ for j in line:
+ self.neighbors_[j].add(i)
+
+ self.weights_ = weights
+ # This is where the main computation happens
+ self.leaf_labels_, self.children_, self.diagram_, self.max_weight_per_cc_ = hierarchy(self.neighbors_, weights)
+ self.n_leaves_ = len(self.max_weight_per_cc_) + len(self.children_)
+ assert self.leaf_labels_.max() + 1 == len(self.max_weight_per_cc_) + len(self.children_)
+ # TODO: deduplicate this code with the setters below
+ if self.__merge_threshold:
+ assert not self.__n_clusters
+ self.__n_clusters = numpy.count_nonzero(
+ self.diagram_[:, 0] - self.diagram_[:, 1] > self.__merge_threshold
+ ) + len(self.max_weight_per_cc_)
+ if self.__n_clusters:
+ # TODO: set corresponding merge_threshold?
+ renaming = merge(self.children_, self.n_leaves_, self.__n_clusters)
+ self.labels_ = renaming[self.leaf_labels_]
+ # In case the user asked for something impossible.
+ # TODO: check for impossible situations before calling merge.
+ self.__n_clusters = self.labels_.max() + 1
+ else:
+ self.labels_ = self.leaf_labels_
+ self.__n_clusters = self.n_leaves_
+ return self
+
+ def fit_predict(self, X, y=None, weights=None):
+ """
+ Equivalent to fit(), and returns the `labels_`.
+ """
+ return self.fit(X, y, weights).labels_
+
+ # TODO: add argument k or threshold? Have a version where you can click and it shows the line and the corresponding k?
+ def plot_diagram(self):
+ """
+ """
+ import matplotlib.pyplot as plt
+
+ l = self.max_weight_per_cc_.min()
+ r = self.max_weight_per_cc_.max()
+ if self.diagram_.size > 0:
+ plt.plot(self.diagram_[:, 0], self.diagram_[:, 1], "o", color="red")
+ l = min(l, self.diagram_[:, 1].min())
+ r = max(r, self.diagram_[:, 0].max())
+ if l == r:
+ if l > 0:
+ l, r = 0.9 * l, 1.1 * r
+ elif l < 0:
+ l, r = 1.1 * l, 0.9 * r
+ else:
+ l, r = -1.0, 1.0
+ plt.plot([l, r], [l, r])
+ plt.plot(
+ self.max_weight_per_cc_, numpy.full(self.max_weight_per_cc_.shape, 1.1 * l - 0.1 * r), "o", color="green"
+ )
+ plt.show()
+
+ # Use set_params instead?
+ @property
+ def n_clusters_(self):
+ return self.__n_clusters
+
+ @n_clusters_.setter
+ def n_clusters_(self, n_clusters):
+ if n_clusters == self.__n_clusters:
+ return
+ self.__n_clusters = n_clusters
+ self.__merge_threshold = None
+ if hasattr(self, "leaf_labels_"):
+ renaming = merge(self.children_, self.n_leaves_, self.__n_clusters)
+ self.labels_ = renaming[self.leaf_labels_]
+ # In case the user asked for something impossible
+ self.__n_clusters = self.labels_.max() + 1
+
+ @property
+ def merge_threshold_(self):
+ return self.__merge_threshold
+
+ @merge_threshold_.setter
+ def merge_threshold_(self, merge_threshold):
+ if merge_threshold == self.__merge_threshold:
+ return
+ if hasattr(self, "leaf_labels_"):
+ self.n_clusters_ = numpy.count_nonzero(self.diagram_[:, 0] - self.diagram_[:, 1] > merge_threshold) + len(
+ self.max_weight_per_cc_
+ )
+ else:
+ self.__n_clusters = None
+ self.__merge_threshold = merge_threshold