question: public ArrayRealVector ( ArrayRealVector v1 , ArrayRealVector v2 ) { data = new double [ v1 . data . length + v2 . data . length ] ; System . arraycopy ( v1 . data , 0 , data , 0 , v1 . data . length ) ; System . arraycopy ( v2 . data , 0 , data , v1 . data . length , v2 . data . length ) ; }
target:  Construct a vector by appending one vector to another vector.