sklearn.manifold
.locally_linear_embedding¶
- sklearn.manifold.locally_linear_embedding(X, *, n_neighbors, n_components, reg=0.001, eigen_solver='auto', tol=1e-06, max_iter=100, method='standard', hessian_tol=0.0001, modified_tol=1e-12, random_state=None, n_jobs=None)[source]¶
Perform a Locally Linear Embedding analysis on the data.
Read more in the User Guide.
- Parameters:
- X{array-like, NearestNeighbors}
Sample data, shape = (n_samples, n_features), in the form of a numpy array or a NearestNeighbors object.
- n_neighborsint
Number of neighbors to consider for each point.
- n_componentsint
Number of coordinates for the manifold.
- regfloat, default=1e-3
Regularization constant, multiplies the trace of the local covariance matrix of the distances.
- eigen_solver{‘auto’, ‘arpack’, ‘dense’}, default=’auto’
auto : algorithm will attempt to choose the best method for input data
- arpackuse arnoldi iteration in shift-invert mode.
For this method, M may be a dense matrix, sparse matrix, or general linear operator. Warning: ARPACK can be unstable for some problems. It is best to try several random seeds in order to check results.
- denseuse standard dense matrix operations for the eigenvalue
decomposition. For this method, M must be an array or matrix type. This method should be avoided for large problems.
- tolfloat, default=1e-6
Tolerance for ‘arpack’ method Not used if eigen_solver==’dense’.
- max_iterint, default=100
Maximum number of iterations for the arpack solver.
- method{‘standard’, ‘hessian’, ‘modified’, ‘ltsa’}, default=’standard’
- standarduse the standard locally linear embedding algorithm.
see reference [1]
- hessianuse the Hessian eigenmap method. This method requires
n_neighbors > n_components * (1 + (n_components + 1) / 2. see reference [2]
- modifieduse the modified locally linear embedding algorithm.
see reference [3]
- ltsause local tangent space alignment algorithm
see reference [4]
- hessian_tolfloat, default=1e-4
Tolerance for Hessian eigenmapping method. Only used if method == ‘hessian’.
- modified_tolfloat, default=1e-12
Tolerance for modified LLE method. Only used if method == ‘modified’.
- random_stateint, RandomState instance, default=None
Determines the random number generator when
solver
== ‘arpack’. Pass an int for reproducible results across multiple function calls. See Glossary.- n_jobsint or None, default=None
The number of parallel jobs to run for neighbors search.
None
means 1 unless in ajoblib.parallel_backend
context.-1
means using all processors. See Glossary for more details.
- Returns:
- Yarray-like, shape [n_samples, n_components]
Embedding vectors.
- squared_errorfloat
Reconstruction error for the embedding vectors. Equivalent to
norm(Y - W Y, 'fro')**2
, where W are the reconstruction weights.
References
[1]Roweis, S. & Saul, L. Nonlinear dimensionality reduction by locally linear embedding. Science 290:2323 (2000).
[2]Donoho, D. & Grimes, C. Hessian eigenmaps: Locally linear embedding techniques for high-dimensional data. Proc Natl Acad Sci U S A. 100:5591 (2003).
[4]Zhang, Z. & Zha, H. Principal manifolds and nonlinear dimensionality reduction via tangent space alignment. Journal of Shanghai Univ. 8:406 (2004)
Examples
>>> from sklearn.datasets import load_digits >>> from sklearn.manifold import locally_linear_embedding >>> X, _ = load_digits(return_X_y=True) >>> X.shape (1797, 64) >>> embedding, _ = locally_linear_embedding(X[:100],n_neighbors=5, n_components=2) >>> embedding.shape (100, 2)
Examples using sklearn.manifold.locally_linear_embedding
¶
Swiss Roll And Swiss-Hole Reduction