Package org.apache.lucene.classification.utils

# Class DocToDoubleVectorUtils

java.lang.Object
org.apache.lucene.classification.utils.DocToDoubleVectorUtils

public class DocToDoubleVectorUtils extends Object
utility class for converting Lucene `Document`s to `Double` vectors.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `static Double[]`
  `toDenseLocalFreqDoubleArray(Terms docTerms)`
  create a dense `Double` vector given doc and field term vectors using local frequency of the terms in the doc
  `static Double[]`
  `toSparseLocalFreqDoubleArray(Terms docTerms, Terms fieldTerms)`
  create a sparse `Double` vector given doc and field term vectors using local frequency of the terms in the doc

  ### Methods inherited from class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Method Details

  - ### toSparseLocalFreqDoubleArray

    public static Double[] toSparseLocalFreqDoubleArray(Terms docTerms, Terms fieldTerms) throws IOException
    create a sparse `Double` vector given doc and field term vectors using local frequency of the terms in the doc
    Parameters:
      `docTerms` - term vectors for a given document
      `fieldTerms` - field term vectors
    Returns:
      a sparse vector of `Double`s as an array
    Throws:
      `IOException` - in case accessing the underlying index fails

  - ### toDenseLocalFreqDoubleArray

    public static Double[] toDenseLocalFreqDoubleArray(Terms docTerms) throws IOException
    create a dense `Double` vector given doc and field term vectors using local frequency of the terms in the doc
    Parameters:
      `docTerms` - term vectors for a given document
    Returns:
      a dense vector of `Double`s as an array
    Throws:
      `IOException` - in case accessing the underlying index fails