Skip to content

Latest commit

 

History

History
295 lines (176 loc) · 11.4 KB

SpectralClustering.md

File metadata and controls

295 lines (176 loc) · 11.4 KB

SpectralClustering

Apply clustering to a projection of the normalized Laplacian.

In practice Spectral Clustering is very useful when the structure of the individual clusters is highly non-convex, or more generally when a measure of the center and spread of the cluster is not a suitable description of the complete cluster, such as when clusters are nested circles on the 2D plane.

If the affinity matrix is the adjacency matrix of a graph, this method can be used to find normalized graph cuts [1], [2].

When calling fit, an affinity matrix is constructed using either a kernel function such the Gaussian (aka RBF) kernel with Euclidean distance d(X, X):

Python Reference

Constructors

constructor()

Signature

new SpectralClustering(opts?: object): SpectralClustering;

Parameters

Name Type Description
opts? object -
opts.affinity? string ‘nearest_neighbors’: construct the affinity matrix by computing a graph of nearest neighbors. Default Value 'rbf'
opts.assign_labels? "kmeans" | "discretize" | "cluster_qr" The strategy for assigning labels in the embedding space. There are two ways to assign labels after the Laplacian embedding. k-means is a popular choice, but it can be sensitive to initialization. Discretization is another approach which is less sensitive to random initialization [3]. The cluster_qr method [5] directly extract clusters from eigenvectors in spectral clustering. In contrast to k-means and discretization, cluster_qr has no tuning parameters and runs no iterations, yet may outperform k-means and discretization in terms of both quality and speed. Default Value 'kmeans'
opts.coef0? number Zero coefficient for polynomial and sigmoid kernels. Ignored by other kernels. Default Value 1
opts.degree? number Degree of the polynomial kernel. Ignored by other kernels. Default Value 3
opts.eigen_solver? "arpack" | "lobpcg" | "amg" The eigenvalue decomposition strategy to use. AMG requires pyamg to be installed. It can be faster on very large, sparse problems, but may also lead to instabilities. If undefined, then 'arpack' is used. See [4] for more details regarding 'lobpcg'.
opts.eigen_tol? number Stopping criterion for eigen decomposition of the Laplacian matrix. If eigen\_tol="auto" then the passed tolerance will depend on the eigen\_solver: Default Value 'auto'
opts.gamma? number Kernel coefficient for rbf, poly, sigmoid, laplacian and chi2 kernels. Ignored for affinity='nearest\_neighbors'. Default Value 1
opts.kernel_params? any Parameters (keyword arguments) and values for kernel passed as callable object. Ignored by other kernels.
opts.n_clusters? number The dimension of the projection subspace. Default Value 8
opts.n_components? number Number of eigenvectors to use for the spectral embedding. If undefined, defaults to n\_clusters.
opts.n_init? number Number of time the k-means algorithm will be run with different centroid seeds. The final results will be the best output of n_init consecutive runs in terms of inertia. Only used if assign\_labels='kmeans'. Default Value 10
opts.n_jobs? number The number of parallel jobs to run when affinity='nearest\_neighbors' or affinity='precomputed\_nearest\_neighbors'. The neighbors search will be done in parallel. undefined means 1 unless in a joblib.parallel\_backend context. \-1 means using all processors. See Glossary for more details.
opts.n_neighbors? number Number of neighbors to use when constructing the affinity matrix using the nearest neighbors method. Ignored for affinity='rbf'. Default Value 10
opts.random_state? number A pseudo random number generator used for the initialization of the lobpcg eigenvectors decomposition when eigen\_solver \== 'amg', and for the K-Means initialization. Use an int to make the results deterministic across calls (See Glossary).
opts.verbose? boolean Verbosity mode. Default Value false

Returns

SpectralClustering

Defined in: generated/cluster/SpectralClustering.ts:27

Methods

dispose()

Disposes of the underlying Python resources.

Once dispose() is called, the instance is no longer usable.

Signature

dispose(): Promise<void>;

Returns

Promise<void>

Defined in: generated/cluster/SpectralClustering.ts:200

fit()

Perform spectral clustering from features, or affinity matrix.

Signature

fit(opts: object): Promise<any>;

Parameters

Name Type Description
opts object -
opts.X? ArrayLike Training instances to cluster, similarities / affinities between instances if affinity='precomputed', or distances between instances if affinity='precomputed\_nearest\_neighbors. If a sparse matrix is provided in a format other than csr\_matrix, csc\_matrix, or coo\_matrix, it will be converted into a sparse csr\_matrix.
opts.y? any Not used, present here for API consistency by convention.

Returns

Promise<any>

Defined in: generated/cluster/SpectralClustering.ts:217

fit_predict()

Perform spectral clustering on X and return cluster labels.

Signature

fit_predict(opts: object): Promise<ArrayLike>;

Parameters

Name Type Description
opts object -
opts.X? ArrayLike Training instances to cluster, similarities / affinities between instances if affinity='precomputed', or distances between instances if affinity='precomputed\_nearest\_neighbors. If a sparse matrix is provided in a format other than csr\_matrix, csc\_matrix, or coo\_matrix, it will be converted into a sparse csr\_matrix.
opts.y? any Not used, present here for API consistency by convention.

Returns

Promise<ArrayLike>

Defined in: generated/cluster/SpectralClustering.ts:257

get_metadata_routing()

Get metadata routing of this object.

Please check User Guide on how the routing mechanism works.

Signature

get_metadata_routing(opts: object): Promise<any>;

Parameters

Name Type Description
opts object -
opts.routing? any A MetadataRequest encapsulating routing information.

Returns

Promise<any>

Defined in: generated/cluster/SpectralClustering.ts:301

init()

Initializes the underlying Python resources.

This instance is not usable until the Promise returned by init() resolves.

Signature

init(py: PythonBridge): Promise<void>;

Parameters

Name Type
py PythonBridge

Returns

Promise<void>

Defined in: generated/cluster/SpectralClustering.ts:140

Properties

_isDisposed

boolean = false

Defined in: generated/cluster/SpectralClustering.ts:25

_isInitialized

boolean = false

Defined in: generated/cluster/SpectralClustering.ts:24

_py

PythonBridge

Defined in: generated/cluster/SpectralClustering.ts:23

id

string

Defined in: generated/cluster/SpectralClustering.ts:20

opts

any

Defined in: generated/cluster/SpectralClustering.ts:21

Accessors

affinity_matrix_

Affinity matrix used for clustering. Available only after calling fit.

Signature

affinity_matrix_(): Promise<ArrayLike[]>;

Returns

Promise<ArrayLike[]>

Defined in: generated/cluster/SpectralClustering.ts:339

feature_names_in_

Names of features seen during fit. Defined only when X has feature names that are all strings.

Signature

feature_names_in_(): Promise<ArrayLike>;

Returns

Promise<ArrayLike>

Defined in: generated/cluster/SpectralClustering.ts:420

labels_

Labels of each point

Signature

labels_(): Promise<ArrayLike>;

Returns

Promise<ArrayLike>

Defined in: generated/cluster/SpectralClustering.ts:366

n_features_in_

Number of features seen during fit.

Signature

n_features_in_(): Promise<number>;

Returns

Promise<number>

Defined in: generated/cluster/SpectralClustering.ts:393

py

Signature

py(): PythonBridge;

Returns

PythonBridge

Defined in: generated/cluster/SpectralClustering.ts:127

Signature

py(pythonBridge: PythonBridge): void;

Parameters

Name Type
pythonBridge PythonBridge

Returns

void

Defined in: generated/cluster/SpectralClustering.ts:131