Class TermDocumentMatrixBuilder

java.lang.Object
org.carrot2.attrs.AttrComposite
org.carrot2.text.vsm.TermDocumentMatrixBuilder
All Implemented Interfaces:
AcceptingVisitor

public class TermDocumentMatrixBuilder extends AttrComposite
Builds a term document matrix based on the provided PreprocessingContext.
  • Field Details

    • boostedFieldWeight

      public final AttrDouble boostedFieldWeight
      The extra weight to apply to words that appeared in boosted fields. The larger the value, the stronger the boost.
    • boostFields

      public AttrStringArray boostFields
      A list fields for which to apply extra weight. Content of fields provided in this parameter can be given more weight during clustering. You may want to boost, for example, the title field with the assumption that it accurately summarizes the content of the whole document.
    • maximumMatrixSize

      public final AttrInteger maximumMatrixSize
      Maximum number of elements the term-document matrix can have. The larger the allowed matrix size, the more accurate, time- and memory-consuming clustering.
    • maxWordDf

      public final AttrDouble maxWordDf
      Maximum document frequency allowed for words as a fraction of all documents. Words with document frequency larger than maxWordDf will be ignored. For example, when maxWordDf is 0.4, words appearing in more than 40% of documents will be be ignored. A value of 1.0 means that all words will be taken into account, no matter in how many documents they appear.

      This parameter may be useful when certain words appear in most of the input documents (e.g. company name from header or footer) and such words dominate the cluster labels. In such case, setting it to a value lower than 1.0 (e.g. 0.9) may improve the clusters.

      Another useful application of this parameter is when there is a need to generate only very specific clusters, that is clusters containing small numbers of documents. This can be achieved by setting maxWordDf to extremely low values: 0.1 or 0.05.

    • termWeighting

      public TermWeighting termWeighting
      Method for calculating weights of words in the term-document matrices.
  • Constructor Details

    • TermDocumentMatrixBuilder

      public TermDocumentMatrixBuilder()
  • Method Details

    • buildTermDocumentMatrix

      public void buildTermDocumentMatrix(VectorSpaceModelContext vsmContext)
      Builds a term-document matrix from data provided in the context, stores the result in there.
    • contantOrderIntIntHashMap

      public static final com.carrotsearch.hppc.IntIntHashMap contantOrderIntIntHashMap(int seed)
    • buildTermPhraseMatrix

      public void buildTermPhraseMatrix(VectorSpaceModelContext context)
      Builds a term-phrase matrix in the same space as the main term-document matrix. If the processing context contains no phrases, VectorSpaceModelContext.termPhraseMatrix will remain null.