A note on the $$CQ$$ algorithm for the split feasibility problem.(English)Zbl 1080.65033

The authors present modifications to the $$CQ$$ algorithm proposed by Ch. Byrne [Inverse Probl. 18, No. 2, 441–453 (2002; Zbl 0996.65048)] and to the relaxed $$CQ$$ algorithm proposed by Q. Z. Yang [Inverse Probl. 20, 1261–1266 (2004; Zbl 1066.65047)] to solve the split feasibility problem $$x^{k+1}=P_C(x^k-yA^T(P_Q-I)Ax^k)$$ by adopting Armijo-like searches. The modified algorithm need not compute matrix inverses and the largest eigenvalue of the matrix $$A^TA$$. It provides a sufficient decrease of the objective function at each iteration by a judicious choice of the stepsize and can identify the existence of solutions by the iterative sequence. The convergence of the modified algorithms is established under mild conditions.

MSC:

 65F30 Other matrix algorithms (MSC2010) 65F10 Iterative numerical methods for linear systems

Citations:

Zbl 0996.65048; Zbl 1066.65047
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