lunr.Builder.prototype.createFieldVectors = function()

in styles/lunr.js [2205:2240]

• 25 lines of code
• 3 McCabe index (conditional complexity)

lunr.Builder.prototype.createFieldVectors = function () {
  var fieldVectors = {},
      fieldRefs = Object.keys(this.fieldTermFrequencies),
      fieldRefsLength = fieldRefs.length

  for (var i = 0; i < fieldRefsLength; i++) {
    var fieldRef = lunr.FieldRef.fromString(fieldRefs[i]),
        field = fieldRef.fieldName,
        fieldLength = this.fieldLengths[fieldRef],
        fieldVector = new lunr.Vector,
        termFrequencies = this.fieldTermFrequencies[fieldRef],
        terms = Object.keys(termFrequencies),
        termsLength = terms.length

    for (var j = 0; j < termsLength; j++) {
      var term = terms[j],
          tf = termFrequencies[term],
          termIndex = this.invertedIndex[term]._index,
          idf = lunr.idf(this.invertedIndex[term], this.documentCount),
          score = idf * ((this._k1 + 1) * tf) / (this._k1 * (1 - this._b + this._b * (fieldLength / this.averageFieldLength[field])) + tf),
          scoreWithPrecision = Math.round(score * 1000) / 1000
          // Converts 1.23456789 to 1.234.
          // Reducing the precision so that the vectors take up less
          // space when serialised. Doing it now so that they behave
          // the same before and after serialisation. Also, this is
          // the fastest approach to reducing a number's precision in
          // JavaScript.

      fieldVector.insert(termIndex, scoreWithPrecision)
    }

    fieldVectors[fieldRef] = fieldVector
  }

  this.fieldVectors = fieldVectors
}