The following node is available in the Open Source KNIME predictive analytics and data mining platform version 2.7.1. Discover over 1000 other nodes, as well as enterprise functionality at http://knime.com.

IDF

Computes the inverse document frequency (idf) of each term according to the given set of documents and adds a column containing the idf value. The value for term t is computed as follows: idf(t) = log(1 + (f(D) / f(d, t)),
where f(D) is the number of all documents and f(d, t) is the number of documents containing term t.

Dialog Options

Document selection
Document Column
Specifies the document column to use for frequency counting.

Ports

Input Ports
0 The input table which contains terms and documents.
Output Ports
0 The output table which contains terms documents and a corresponding frequency value.
This node is contained in KNIME Textprocessing Plug-in provided by KNIME GmbH, Konstanz, Germany.