`gemclus.mlp`.MLPModel¶

class gemclus.mlp.MLPModel(n_clusters=3, gemini='mmd_ova', max_iter=1000, learning_rate=0.001, solver='adam', n_hidden_dim=20, batch_size=None, verbose=False, random_state=None)[source]¶

Implementation of a two-layer neural network as a clustering distribution \(p(y|x)\). Any GEMINI can be used to train this model.

Parameters:

n_clustersint, default=3

The maximum number of clusters to form as well as the number of output neurons in the neural network.

gemini: str, GEMINI instance or None, default=”mmd_ova”

GEMINI objective used to train this discriminative model. Can be “mmd_ova”, “mmd_ovo”, “wasserstein_ova”, “wasserstein_ovo”, “mi” or other GEMINI available in gemclus.gemini.AVAILABLE_GEMINI. Default GEMINIs involve the Euclidean metric or linear kernel. To incorporate custom metrics, a GEMINI can also be passed as an instance. If set to None, the GEMINI will be MMD OvA with linear kernel.

max_iter: int, default=1000

Maximum number of epochs to perform gradient descent in a single run.

learning_rate: float, default=1e-3

Initial learning rate used. It controls the step-size in updating the weights.

n_hidden_dim: int, default=20

The number of neurons in the hidden layer of the neural network.

solver: {‘sgd’,’adam’}, default=’adam’

The solver for weight optimisation.

‘sgd’ refers to stochastic gradient descent.
‘adam’ refers to a stochastic gradient-based optimiser proposed by Kingma, Diederik and Jimmy Ba.

batch_size: int, default=None

The size of batches during gradient descent training. If set to None, the whole data will be considered.

verbose: bool, default=False

Whether to print progress messages to stdout

random_state: int, RandomState instance, default=None

Determines random number generation for weights and bias initialisation. Pass an int for reproducible results across multiple function calls.

See also

MLPMMD: two-layer neural network trained for clustering with the MMD GEMINI
MLPWasserstein: two-layer neural network trained for clustering with the Wasserstein GEMINI

References

GEMINI - Generalised Mutual Information for Discriminative Clustering: Louis Ohl, Pierre-Alexandre Mattei, Charles Bouveyron, Warith Harchaoui, Mickaël Leclercq, Arnaud Droit, Frederic Precioso

Examples

>>> from sklearn.datasets import load_iris
>>> from gemclus.mlp import MLPModel
>>> X,y=load_iris(return_X_y=True)
>>> clf = MLPModel(gemini="mi",random_state=0).fit(X)
>>> clf.predict(X[:2,:])
array([0, 0])
>>> clf.predict_proba(X[:2,:]).shape
(2, 3)
>>> clf.score(X)
0.6325592616

Attributes:

W1_: ndarray, shape (n_features, n_hidden_dim): The linear weights of the first layer
b1_: ndarray of shape (1, n_hidden_dim): The biases of the first layer
W2_: ndarray of shape (n_hidden_dim, n_clusters): The linear weights of the hidden layer
b2_: ndarray of shape (1, n_clusters): The biases of the hidden layer
optimiser_: `AdamOptimizer` or `SGDOptimizer`: The optimisation algorithm used for training depending on the chosen solver parameter.
labels_: ndarray of shape (n_samples): The labels that were assigned to the samples passed to the fit() method.
n_iter_: int: The number of iterations that the model took for converging.
H_: ndarray of shape (n_samples, n_hidden_dim): The hidden representation of the samples after fitting.OvA

__init__(n_clusters=3, gemini='mmd_ova', max_iter=1000, learning_rate=0.001, solver='adam', n_hidden_dim=20, batch_size=None, verbose=False, random_state=None)[source]¶

fit(X, y=None)¶

Compute GEMINI clustering.

Parameters:

X{array-like, sparse matrix} of shape (n_samples, n_features): Training instances to cluster.
yndarray of shape (n_samples, n_samples), default=None: Use this parameter to give a precomputed affinity metric if the option “precomputed” was passed during construction. Otherwise, it is not used and present here for API consistency by convention.

Returns:

selfobject: Fitted estimator.

fit_predict(X, y=None)¶

Compute GEMINI clustering and returns the predicted clusters.

Parameters:

X{array-like, sparse matrix} of shape (n_samples, n_features): Training instances to cluster.
yndarray of shape (n_samples, n_samples), default=None: Use this parameter to give a precomputed affinity metric if the option “precomputed” was passed during construction. Otherwise, it is not used and present here for API consistency by convention.

Returns:

y_predndarray of shape (n_samples,): Vector containing the cluster label for each sample.

get_gemini()¶

Initialise a gemclus.GEMINI instance that will be used to train the model.

Returns:

gemini: a GEMINI instance

get_metadata_routing()¶

Get metadata routing of this object.

Please check User Guide on how the routing mechanism works.

Returns:

routingMetadataRequest: A MetadataRequest encapsulating routing information.

get_params(deep=True)¶

Get parameters for this estimator.

Parameters:

deepbool, default=True: If True, will return the parameters for this estimator and contained subobjects that are estimators.

Returns:

paramsdict: Parameter names mapped to their values.

predict(X)¶

Return the cluster membership of samples. This can only be called after the model was fit to some data.

Parameters:

X{array-like, sparse matrix}, shape (n_samples, n_features): The input samples.

Returns:

yndarray of shape (n_samples,): The label for each sample is the label of the closest sample seen during fit.

predict_proba(X)¶

Probability estimates that are the output of the neural network p(y|x). The returned estimates for all classes are ordered by the label of classes.

Parameters:

X{array-like, sparse matrix} of shape (n_samples, n_features): Vector to be scored, where n_samples is the number of samples and n_features is the number of features.

Returns:

Tarray-like of shape (n_samples, n_clusters): Returns the probability of the sample for each cluster in the model.

score(X, y=None)¶

Return the value of the GEMINI evaluated on the given test data.

Parameters:

X{array-like, sparse matrix} of shape (n_samples, n_features): Test samples.
yndarray of shape (n_samples, n_samples), default=None: Use this parameter to give a precomputed affinity metric if the option “precomputed” was passed during construction. Otherwise, it is not used and present here for API consistency by convention.

Returns:

scorefloat: GEMINI evaluated on the output of self.predict(X).

set_params(**params)¶

Set the parameters of this estimator.

The method works on simple estimators as well as on nested objects (such as Pipeline). The latter have parameters of the form <component>__<parameter> so that it’s possible to update each component of a nested object.

Parameters:

**paramsdict: Estimator parameters.

Returns:

selfestimator instance: Estimator instance.

Examples using `gemclus.mlp.MLPModel`¶

An introducing example to clustering with an MLP and the MMD GEMINI

Drawing a decision boundary between two interlacing moons

Comparative clustering of circles dataset with kernel change

Feature selection using the Sparse MMD OvA (MLP)

gemclus.mlp.MLPModel¶

Examples using gemclus.mlp.MLPModel¶

`gemclus.mlp`.MLPModel¶

Examples using `gemclus.mlp.MLPModel`¶