Biconjugate gradient stabilized method

The biconjugate gradient stabilized method, usually abbreviated BiCGSTAB, is an iterative method for the numerical solution of nonsymmetric linear systems. H. A. van der Vorst developed it as a variant of the biconjugate gradient method (BiCG), and it converges faster and more smoothly than the original BiCG as well as other variants such as the conjugate gradient squared method (CGS). It belongs to the family of Krylov subspace methods. A practical advantage over the original BiCG method is that it does not require multiplication by the transpose of the system matrix, which simplifies its use when only products with the matrix itself are available.