Krylov subspace
（重定向自Krylov sequence）
In linear algebra, the order-r Krylov subspace generated by an n-by-n matrix A and a vector b of dimension n is the linear subspace spanned by the images of b under the first r powers of A (starting from ![A^0=I](/Images/godic/202501/22/7edbb987a329a9bfa6450b1abf746bf80653.png")
), that is,