package sklearn

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sklearn
- Sklearn

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type tag = [

| `LatentDirichletAllocation

]

type t =
  [ `BaseEstimator | `LatentDirichletAllocation | `Object | `TransformerMixin ]
    Obj.t

val of_pyobject : Py.Object.t -> t

val to_pyobject : [> tag ] Obj.t -> Py.Object.t

val as_transformer : t -> [ `TransformerMixin ] Obj.t

val as_estimator : t -> [ `BaseEstimator ] Obj.t

val create : 
  ?n_components:int ->
  ?doc_topic_prior:float ->
  ?topic_word_prior:float ->
  ?learning_method:[ `Batch | `Online ] ->
  ?learning_decay:float ->
  ?learning_offset:float ->
  ?max_iter:int ->
  ?batch_size:int ->
  ?evaluate_every:int ->
  ?total_samples:int ->
  ?perp_tol:float ->
  ?mean_change_tol:float ->
  ?max_doc_update_iter:int ->
  ?n_jobs:int ->
  ?verbose:int ->
  ?random_state:int ->
  unit ->
  t

Latent Dirichlet Allocation with online variational Bayes algorithm

.. versionadded:: 0.17

Read more in the :ref:`User Guide <LatentDirichletAllocation>`.

Parameters ---------- n_components : int, optional (default=10) Number of topics.

.. versionchanged:: 0.19 ``n_topics `` was renamed to ``n_components``

doc_topic_prior : float, optional (default=None) Prior of document topic distribution `theta`. If the value is None, defaults to `1 / n_components`. In 1_, this is called `alpha`.

topic_word_prior : float, optional (default=None) Prior of topic word distribution `beta`. If the value is None, defaults to `1 / n_components`. In 1_, this is called `eta`.

learning_method : 'batch' | 'online', default='batch' Method used to update `_component`. Only used in :meth:`fit` method. In general, if the data size is large, the online update will be much faster than the batch update.

Valid options::

'batch': Batch variational Bayes method. Use all training data in each EM update. Old `components_` will be overwritten in each iteration. 'online': Online variational Bayes method. In each EM update, use mini-batch of training data to update the ``components_`` variable incrementally. The learning rate is controlled by the ``learning_decay`` and the ``learning_offset`` parameters.

.. versionchanged:: 0.20 The default learning method is now ``'batch'``.

learning_decay : float, optional (default=0.7) It is a parameter that control learning rate in the online learning method. The value should be set between (0.5, 1.0] to guarantee asymptotic convergence. When the value is 0.0 and batch_size is ``n_samples``, the update method is same as batch learning. In the literature, this is called kappa.

learning_offset : float, optional (default=10.) A (positive) parameter that downweights early iterations in online learning. It should be greater than 1.0. In the literature, this is called tau_0.

max_iter : integer, optional (default=10) The maximum number of iterations.

batch_size : int, optional (default=128) Number of documents to use in each EM iteration. Only used in online learning.

evaluate_every : int, optional (default=0) How often to evaluate perplexity. Only used in `fit` method. set it to 0 or negative number to not evaluate perplexity in training at all. Evaluating perplexity can help you check convergence in training process, but it will also increase total training time. Evaluating perplexity in every iteration might increase training time up to two-fold.

total_samples : int, optional (default=1e6) Total number of documents. Only used in the :meth:`partial_fit` method.

perp_tol : float, optional (default=1e-1) Perplexity tolerance in batch learning. Only used when ``evaluate_every`` is greater than 0.

mean_change_tol : float, optional (default=1e-3) Stopping tolerance for updating document topic distribution in E-step.

max_doc_update_iter : int (default=100) Max number of iterations for updating document topic distribution in the E-step.

n_jobs : int or None, optional (default=None) The number of jobs to use in the E-step. ``None`` means 1 unless in a :obj:`joblib.parallel_backend` context. ``-1`` means using all processors. See :term:`Glossary <n_jobs>` for more details.

verbose : int, optional (default=0) Verbosity level.

random_state : int, RandomState instance, default=None Pass an int for reproducible results across multiple function calls. See :term:`Glossary <random_state>`.

Attributes ---------- components_ : array, n_components, n_features Variational parameters for topic word distribution. Since the complete conditional for topic word distribution is a Dirichlet, ``components_i, j`` can be viewed as pseudocount that represents the number of times word `j` was assigned to topic `i`. It can also be viewed as distribution over the words for each topic after normalization: ``model.components_ / model.components_.sum(axis=1):, np.newaxis``.

n_batch_iter_ : int Number of iterations of the EM step.

n_iter_ : int Number of passes over the dataset.

bound_ : float Final perplexity score on training set.

doc_topic_prior_ : float Prior of document topic distribution `theta`. If the value is None, it is `1 / n_components`.

topic_word_prior_ : float Prior of topic word distribution `beta`. If the value is None, it is `1 / n_components`.

Examples -------- >>> from sklearn.decomposition import LatentDirichletAllocation >>> from sklearn.datasets import make_multilabel_classification >>> # This produces a feature matrix of token counts, similar to what >>> # CountVectorizer would produce on text. >>> X, _ = make_multilabel_classification(random_state=0) >>> lda = LatentDirichletAllocation(n_components=5, ... random_state=0) >>> lda.fit(X) LatentDirichletAllocation(...) >>> # get topics for some given samples: >>> lda.transform(X-2:) array([0.00360392, 0.25499205, 0.0036211 , 0.64236448, 0.09541846], [0.15297572, 0.00362644, 0.44412786, 0.39568399, 0.003586 ])

References ---------- .. 1 'Online Learning for Latent Dirichlet Allocation', Matthew D. Hoffman, David M. Blei, Francis Bach, 2010

2 'Stochastic Variational Inference', Matthew D. Hoffman, David M. Blei, Chong Wang, John Paisley, 2013

3 Matthew D. Hoffman's onlineldavb code. Link: https://github.com/blei-lab/onlineldavb

val fit : ?y:Py.Object.t -> x:[> `ArrayLike ] Np.Obj.t -> [> tag ] Obj.t -> t

Learn model for the data X with variational Bayes method.

When `learning_method` is 'online', use mini-batch update. Otherwise, use batch update.

Parameters ---------- X : array-like or sparse matrix, shape=(n_samples, n_features) Document word matrix.

y : Ignored

Returns ------- self

val fit_transform : 
  ?y:[> `ArrayLike ] Np.Obj.t ->
  ?fit_params:(string * Py.Object.t) list ->
  x:[> `ArrayLike ] Np.Obj.t ->
  [> tag ] Obj.t ->
  [> `ArrayLike ] Np.Obj.t

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 : array-like, sparse matrix, dataframe of shape (n_samples, n_features)

y : ndarray of shape (n_samples,), default=None Target values.

**fit_params : dict Additional fit parameters.

Returns ------- X_new : ndarray array of shape (n_samples, n_features_new) Transformed array.

val get_params : ?deep:bool -> [> tag ] Obj.t -> Dict.t

Get parameters for this estimator.

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

Returns ------- params : mapping of string to any Parameter names mapped to their values.

val partial_fit : 
  ?y:Py.Object.t ->
  x:[> `ArrayLike ] Np.Obj.t ->
  [> tag ] Obj.t ->
  t

Online VB with Mini-Batch update.

Parameters ---------- X : array-like or sparse matrix, shape=(n_samples, n_features) Document word matrix.

y : Ignored

Returns ------- self

val perplexity : 
  ?sub_sampling:bool ->
  x:[> `ArrayLike ] Np.Obj.t ->
  [> tag ] Obj.t ->
  float

Calculate approximate perplexity for data X.

Perplexity is defined as exp(-1. * log-likelihood per word)

.. versionchanged:: 0.19 *doc_topic_distr* argument has been deprecated and is ignored because user no longer has access to unnormalized distribution

Parameters ---------- X : array-like or sparse matrix, n_samples, n_features Document word matrix.

sub_sampling : bool Do sub-sampling or not.

Returns ------- score : float Perplexity score.

val score : 
  ?y:Py.Object.t ->
  x:[> `ArrayLike ] Np.Obj.t ->
  [> tag ] Obj.t ->
  float

Calculate approximate log-likelihood as score.

Parameters ---------- X : array-like or sparse matrix, shape=(n_samples, n_features) Document word matrix.

y : Ignored

Returns ------- score : float Use approximate bound as score.

val set_params : ?params:(string * Py.Object.t) list -> [> tag ] Obj.t -> t

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.

Parameters ---------- **params : dict Estimator parameters.

Returns ------- self : object Estimator instance.

val transform : 
  x:[> `ArrayLike ] Np.Obj.t ->
  [> tag ] Obj.t ->
  [> `ArrayLike ] Np.Obj.t

Transform data X according to the fitted model.

.. versionchanged:: 0.18 *doc_topic_distr* is now normalized

Parameters ---------- X : array-like or sparse matrix, shape=(n_samples, n_features) Document word matrix.

Returns ------- doc_topic_distr : shape=(n_samples, n_components) Document topic distribution for X.

val components_ : t -> [> `ArrayLike ] Np.Obj.t

Attribute components_: get value or raise Not_found if None.

val components_opt : t -> [> `ArrayLike ] Np.Obj.t option

Attribute components_: get value as an option.

val n_batch_iter_ : t -> int

Attribute n_batch_iter_: get value or raise Not_found if None.

val n_batch_iter_opt : t -> int option

Attribute n_batch_iter_: get value as an option.

val n_iter_ : t -> int

Attribute n_iter_: get value or raise Not_found if None.

val n_iter_opt : t -> int option

Attribute n_iter_: get value as an option.

val bound_ : t -> float

Attribute bound_: get value or raise Not_found if None.

val bound_opt : t -> float option

Attribute bound_: get value as an option.

val doc_topic_prior_ : t -> float

Attribute doc_topic_prior_: get value or raise Not_found if None.

val doc_topic_prior_opt : t -> float option

Attribute doc_topic_prior_: get value as an option.

val topic_word_prior_ : t -> float

Attribute topic_word_prior_: get value or raise Not_found if None.

val topic_word_prior_opt : t -> float option

Attribute topic_word_prior_: get value as an option.

val to_string : t -> string

Print the object to a human-readable representation.

val show : t -> string

Print the object to a human-readable representation.

val pp : Format.formatter -> t -> unit

Pretty-print the object to a formatter.