code: public static void normalizeSumOne( TupleDesc_F64 desc ) {
  		double sum = 0;
  		for (int i = 0; i < desc.size(); i++) {
  			double v = desc.value[i];
  			sum += v;
  		}
  		if( sum == 0 )
  			return;
  
  		for (int i = 0; i < desc.size(); i++) {
  			desc.value[i] /= sum;
  		}
  	}
docs: <p>
  Normalized the tuple such that it's sum is equal to 1.
  </p>
  
  <p>
  value[i] = value[i]/sqrt(sum(value[j], for all j))
  </p>
  
  @param desc tuple