LogisticRegressionClassifier

This intent classifier is based on the Logistic Regression Classifier from sklearn. This classifier only looks at sparse features extracted from the Rasa NLU feature pipeline and is a much faster alternative to neural models like DIET.

Configurable Variables

The classifier supports the same parameters as those that are listed in the sklearn documentation. The only difference is:

• there is no warm_start option
• the default class_weight is "balanced"

Base Usage

The configuration file below demonstrates how you might use the this component. In this example we are extracting sparse features with two CountVectorsFeaturizer instances, the first of which produces sparse bag-of-words features, and the second which produces sparse bags-of-character-ngram features.

Note that in the following example, setting the class_weight parameter to None explicitly does have an effect because our default value for this paramter is "balanced".

language: en

pipeline:
- name: WhitespaceTokenizer
- name: CountVectorsFeaturizer
- name: CountVectorsFeaturizer
  analyzer: char_wb
  min_ngram: 1
  max_ngram: 4
- name: rasa_nlu_examples.classifiers.LogisticRegressionClassifier
  class_weight: None

Unlike DIET, this classifier only predicts intents. If you also need entity extraction, you will have to add a separate entity extractor to your config. Below is an example where we have included the CRFEntityExtractor to extract entities.

language: en

pipeline:
- name: WhitespaceTokenizer
- name: LexicalSyntacticFeaturizer
- name: CountVectorsFeaturizer
- name: CountVectorsFeaturizer
  analyzer: char_wb
  min_ngram: 1
  max_ngram: 4
- name: rasa_nlu_examples.classifiers.LogisticRegressionClassifier
- name: CRFEntityExtractor