In mathematics, an H-matrix is a matrix whose comparison matrix is an M-matrix. It is useful in iterative methods.
Definition: Let be a complex matrix. Then comparison matrix M(A) of complex matrix A is defined as where for all and for all . If M(A) is a M-matrix, A is a H-matrix.
Invertible H-matrix guarantees convergence of Gauss–Seidel iterative methods.[1]