DBSCAN
¶
-
class
ibex.sklearn.cluster.
DBSCAN
(eps=0.5, min_samples=5, metric='euclidean', metric_params=None, algorithm='auto', leaf_size=30, p=None, n_jobs=1)¶ Bases:
sklearn.cluster.dbscan_.DBSCAN
,ibex._base.FrameMixin
Note
The documentation following is of the class wrapped by this class. There are some changes, in particular:
- A parameter
X
denotes apandas.DataFrame
. - A parameter
y
denotes apandas.Series
.
Perform DBSCAN clustering from vector array or distance matrix.
DBSCAN - Density-Based Spatial Clustering of Applications with Noise. Finds core samples of high density and expands clusters from them. Good for data which contains clusters of similar density.
Read more in the User Guide.
- eps : float, optional
- The maximum distance between two samples for them to be considered as in the same neighborhood.
- min_samples : int, optional
- The number of samples (or total weight) in a neighborhood for a point to be considered as a core point. This includes the point itself.
- metric : string, or callable
The metric to use when calculating distance between instances in a feature array. If metric is a string or callable, it must be one of the options allowed by metrics.pairwise.calculate_distance for its metric parameter. If metric is “precomputed”, X is assumed to be a distance matrix and must be square. X may be a sparse matrix, in which case only “nonzero” elements may be considered neighbors for DBSCAN.
New in version 0.17: metric precomputed to accept precomputed sparse matrix.
- metric_params : dict, optional
Additional keyword arguments for the metric function.
New in version 0.19.
- algorithm : {‘auto’, ‘ball_tree’, ‘kd_tree’, ‘brute’}, optional
- The algorithm to be used by the NearestNeighbors module to compute pointwise distances and find nearest neighbors. See NearestNeighbors module documentation for details.
- leaf_size : int, optional (default = 30)
- Leaf size passed to BallTree or cKDTree. This can affect the speed of the construction and query, as well as the memory required to store the tree. The optimal value depends on the nature of the problem.
- p : float, optional
- The power of the Minkowski metric to be used to calculate distance between points.
- n_jobs : int, optional (default = 1)
- The number of parallel jobs to run.
If
-1
, then the number of jobs is set to the number of CPU cores.
- core_sample_indices_ : array, shape = [n_core_samples]
- Indices of core samples.
- components_ : array, shape = [n_core_samples, n_features]
- Copy of each core sample found by training.
- labels_ : array, shape = [n_samples]
- Cluster labels for each point in the dataset given to fit(). Noisy samples are given the label -1.
For an example, see examples/cluster/plot_dbscan.py.
This implementation bulk-computes all neighborhood queries, which increases the memory complexity to O(n.d) where d is the average number of neighbors, while original DBSCAN had memory complexity O(n).
Sparse neighborhoods can be precomputed using
NearestNeighbors.radius_neighbors_graph
withmode='distance'
.Ester, M., H. P. Kriegel, J. Sander, and X. Xu, “A Density-Based Algorithm for Discovering Clusters in Large Spatial Databases with Noise”. In: Proceedings of the 2nd International Conference on Knowledge Discovery and Data Mining, Portland, OR, AAAI Press, pp. 226-231. 1996
-
fit
(X, y=None, sample_weight=None)[source]¶ Note
The documentation following is of the class wrapped by this class. There are some changes, in particular:
- A parameter
X
denotes apandas.DataFrame
. - A parameter
y
denotes apandas.Series
.
Perform DBSCAN clustering from features or distance matrix.
- X : array or sparse (CSR) matrix of shape (n_samples, n_features), or array of shape (n_samples, n_samples)
- A feature array, or array of distances between samples if
metric='precomputed'
. - sample_weight : array, shape (n_samples,), optional
- Weight of each sample, such that a sample with a weight of at least
min_samples
is by itself a core sample; a sample with negative weight may inhibit its eps-neighbor from being core. Note that weights are absolute, and default to 1.
y : Ignored
- A parameter
-
fit_predict
(X, y=None, sample_weight=None)[source]¶ Note
The documentation following is of the class wrapped by this class. There are some changes, in particular:
- A parameter
X
denotes apandas.DataFrame
. - A parameter
y
denotes apandas.Series
.
Performs clustering on X and returns cluster labels.
- X : array or sparse (CSR) matrix of shape (n_samples, n_features), or array of shape (n_samples, n_samples)
- A feature array, or array of distances between samples if
metric='precomputed'
. - sample_weight : array, shape (n_samples,), optional
- Weight of each sample, such that a sample with a weight of at least
min_samples
is by itself a core sample; a sample with negative weight may inhibit its eps-neighbor from being core. Note that weights are absolute, and default to 1.
y : Ignored
- y : ndarray, shape (n_samples,)
- cluster labels
- A parameter
- A parameter