@Override
  public double distance(NumberVector v1, NumberVector v2) {
    double d = VectorUtil.dot(v1, v2);
    return (d <= 1) ? 1 - d : 0;
  }
@ Override public double distance ( NumberVector v1 , NumberVector v2 ) { double d = VectorUtil . dot ( v1 , v2 ) ; return ( d <= 1 ) ? 1 - d : 0 ; }
Computes the cosine distance for two given feature vectors.

The cosine distance is computed from the cosine similarity by
<code>1-(cosine similarity)</code>.

@param v1 first feature vector
@param v2 second feature vector
@return the cosine distance for two given feature vectors v1 and v2