gensim logo

gensim
gensim tagline

Get Expert Help

• machine learning, NLP, data mining

• custom SW design, development, optimizations

• corporate trainings & IT consulting

sklearn_api.ldamodel – Scikit learn wrapper for Latent Dirichlet Allocation

sklearn_api.ldamodel – Scikit learn wrapper for Latent Dirichlet Allocation

Scikit learn interface for gensim for easy use of gensim with scikit-learn follows on scikit learn API conventions

class gensim.sklearn_api.ldamodel.LdaTransformer(num_topics=100, id2word=None, chunksize=2000, passes=1, update_every=1, alpha='symmetric', eta=None, decay=0.5, offset=1.0, eval_every=10, iterations=50, gamma_threshold=0.001, minimum_probability=0.01, random_state=None, scorer='perplexity')

Bases: sklearn.base.TransformerMixin, sklearn.base.BaseEstimator

Base LDA module

Sklearn wrapper for LDA model. See gensim.model.LdaModel for parameter details.

scorer specifies the metric used in the score function.

See gensim.models.LdaModel class for description of the other parameters.

fit(X, y=None)

Fit the model according to the given training data. Calls gensim.models.LdaModel

fit_transform(X, y=None, **fit_params)

Fit to data, then transform it.

Fits transformer to X and y with optional parameters fit_params and returns a transformed version of X.

Parameters:
  • X (numpy array of shape [n_samples, n_features]) – Training set.
  • y (numpy array of shape [n_samples]) – Target values.
Returns:

X_new – Transformed array.

Return type:

numpy array of shape [n_samples, n_features_new]

get_params(deep=True)

Get parameters for this estimator.

Parameters:deep (boolean, optional) – If True, will return the parameters for this estimator and contained subobjects that are estimators.
Returns:params – Parameter names mapped to their values.
Return type:mapping of string to any
partial_fit(X)

Train model over X. By default, ‘online (single-pass)’ mode is used for training the LDA model. Configure passes and update_every params at init to choose the mode among :

  • online (single-pass): update_every != None and passes == 1
  • online (multi-pass): update_every != None and passes > 1
  • batch: update_every == None
score(X, y=None)

Compute score reflecting how well the model has fit for the input data.

set_params(**params)

Set the parameters of this estimator.

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

Returns:
Return type:self
transform(docs)

Takes a list of documents as input (‘docs’). Returns a matrix of topic distribution for the given document bow, where a_ij indicates (topic_i, topic_probability_j). The input docs should be in BOW format and can be a list of documents like : [ [(4, 1), (7, 1)], [(9, 1), (13, 1)], [(2, 1), (6, 1)] ] or a single document like : [(4, 1), (7, 1)]