A partially randomized extended Kaczmarz method for solving inconsistent rank-deficient linear systems
摘要
The extended Kaczmarz type methods are often used to solve large inconsistent overdetermined linear systems whose coefficient matrix A is of full column rank. These methods are also applicable to overdetermined linear systems where A is rank-deficient. In this paper, a modified partially randomized extended Kaczmarz method is proposed for solving large inconsistent linear systems with the rank-deficient coefficient matrix. The randomized range finder method proposed by Halko et al. (SIAM Rev 53(2):217–288, 2011) is used to generate a column-orthonormal matrix Q whose range approximates the range of the coefficient matrix A as a preconditioner. Then