BandPC: Learning Residual-Band Preconditioner Combinations for Flexible Conjugate Gradient Solvers
BandPC is a data-driven framework using Graph Neural Networks (GNNs) to predict optimal multi-stage preconditioning strategies for the Flexible Conjugate Gradient (FCG) method. It partitions the solving process into residual-defined stages and learns which preconditioner to use at each stage by mapping matrix structure to performance scores, significantly accelerating convergence on large sparse systems.