Text Classifier Learner

Options

Text input

Column in the input table with the text documents.

Category input

Column in the input table with the pre-assigned categories.

Weight input

(optional) column in the input table which allows weighting differing training documents (a value of 1 means normal weight, for higher values, the learner behaves like adding the particular document n times).

n-gram type

The type of n-grams to be used. n-grams can be created on character and word level.

Min. n-gram length

The minimum length of n-grams to create (i.e. the number of characters or words, depending on n-gram type).

Max. n-gram length

The maximum length of n-grams to create.

Min. term length

(Only effective for n-gram type “word”) The minimum length of a word n-gram in characters to be considered.

Max. term length

(Only effective for n-gram type “word”) The maximum length of a word n-gram in characters to be considered.

Max. term count

The maximum number of terms to extract from each document (useful to speed up processing of huge documents, or to reduce model size in general).

Case sensitive

Activate to treat text documents case sensitively (can improve accuracy in certain cases, but increases model size).

Border padding

Create padded character n-grams at text document’s beginning and end (e.g. for a document starting with “The”, and n-gram length 3, we additionally create features the “##T”, “#Th”. This setting can improve accuracy when classifying very short phrases, but increases model size).

Create skip-grams

When in word mode and n-grams length >= 3, additionally create skip grams. Skip grams allow to model gaps between word groups by leaving out words inside the n-gram. E.g. for the consecutive 3-gram “the quick brown”, the skip gram is “the brown”.

Language-specific settings

Language

The language to use for the language-specific processing (see below; only in case the n-gram type is “word”)

Remove stopwords

Removes stopwords based on a predefined stopword list for the given language.

Stem

Performs stemming using the Snowball stemmer.

Expert settings

Do not stop on memory warnings

Do not listen to KNIME’s memory warnings. Attention: In case this option is enabled, KNIME will become unresponsive when the model size exceeds the memory limit.

Input Ports

Input with pre-categorized text documents. The category has to be given by a separate String column.

Output Ports

The model data of the trained classifier.

Best Friends (Incoming)

• Column Filter (6 %) Streamable
• Partitioning (6 %) 
• Column Rename (4 %) Streamable
• File Reader (3 %) Streamable
• Row Filter (3 %) Streamable
• Joiner (3 %) 
• Row Sampling (3 %) 
• Excel Reader (XLS) (3 %) StreamableDeprecated
• Excel Reader (XLS) (3 %) Streamable
• FeatureTextReader (1 %) 
• Active Learn Loop Start (1 %) 
• CSV Reader (1 %) 
• Loop End (1 %) 
• Counting Loop Start (1 %) 
• Decision Tree Predictor (1 %) 
• K Nearest Neighbor (1 %) StreamableDeprecated
• Scorer (1 %) 
• Random Forest Learner (1 %) Deprecated
• Concatenate (1 %) Streamable
• Auto-Binner (1 %) 
• Case Converter (1 %) Streamable
• Cell Splitter (1 %) Deprecated
• Column Merger (1 %) Streamable
• Constant Value Column (1 %) Streamable
• Cross Joiner (1 %) Streamable
• Equal Size Sampling (1 %) 
• Row Splitter (1 %) Streamable
• Reference Row Filter (1 %) 
• GroupBy (1 %) 
• Missing Value (1 %) 
• Column Splitter (1 %) Streamable
• String Manipulation (1 %) Streamable
• Unpivoting (1 %) 
• Rule-based Row Filter (1 %) Streamable
• Cache (1 %) 
• Similarity Search (1 %) 
• DL4J Feedforward Predictor (Classification) (1 %) 
• Math Formula (1 %) Streamable
• XLS Reader (1 %) Deprecated
• Topic Extractor (Parallel LDA) (1 %) 
• Category To Class (1 %) 
• Chi-Square Keyword Extractor (1 %) 
• Keygraph Keyword Extractor (1 %) 
• Tika Language Detector (1 %) Streamable
• Dictionary Filter (1 %) Streamable
• Punctuation Erasure (1 %) Streamable
• Snowball Stemmer (1 %) Streamable
• PDF Parser (1 %) 
• Document Data Extractor (1 %) Deprecated
• Document Data Extractor (1 %) 
• Strings To Document (1 %) StreamableDeprecated
• Text Classifier Model Pruner (1 %) 
• Dataset Reader (1 %) 
• URL Extractor (1 %) 
• Content Extractor (1 %) 
• HTML Parser (1 %) 
• Show all 56 recommendations

Best Friends (Outgoing)

• Text Classifier Predictor (74 %) 
• Text Classifier Model Pruner (12 %) 
• Text Classifier Model to Table (9 %) 
• Model Writer (2 %) 
• Text Classifier Model Writer (2 %) 

Installation

To use this node in KNIME, install Palladian Nodes for KNIME Workbench from the following update site: