Abstract
The BiCG method has been reformulated in order to show the relation between the IDR(s) method and the BiCGSTAB method. The residuals and the BiCG coefficients of the reformulated BiCG are computed by an alternative formulation which is close to the IDR approach. The variants of hybrid BiCG methods have been developed by using the reformulated BiCG, and are often more effective than their original counterparts. In this paper, we propose variants of hybrid BiCR methods using the alternative formulation of BiCR. Numerical experiments demonstrate that our proposed variants are more effective than the original hybrid BiCR methods.
