AINV Preconditioner

[3NeroN]

Hello,

What is the order of approximation used in AINV preconditioner?

NeroN

[klausbu]

The implemented AINV preconditioner corresponds to the first-order approximation (denoted as D1D1​ in the paper "Algorithm for Sparse Approximate Inverse Preconditioners in the Conjugate Gradient Method" (2013) by Ilya B. Labutin and Irina V. Surodina).