question: private final double preDistance ( NumberVector v1 , NumberVector v2 , final int start , final int end ) { double agg = 0. ; for ( int d = start ; d < end ; d ++ ) { final double xd = v1 . doubleValue ( d ) , yd = v2 . doubleValue ( d ) ; final double delta = ( xd >= yd ) ? xd - yd : yd - xd ; agg += Math . pow ( delta , p ) ; } return agg ; }
target:  Compute unscaled distance in a range of dimensions.