code: public static float sad(TupleDesc_F32 a, TupleDesc_F32 b) {
  
  		float total = 0;
  		for( int i = 0; i < a.value.length; i++ ) {
  			total += Math.abs( a.value[i] - b.value[i]);
  		}
  		return total;
  	}
docs: Sum of absolute difference (SAD) score
  
  @param a First descriptor
  @param b Second descriptor
  @return SAD score