Full multigrid

Finally, it should be noted that the multigrid method can be used as either an iterative process or as a direct solver (the so-called full multigrid or nested iteration method ). 

Full Approximations Scheme (FAS) Multigrid, and Full Multigrid (FMG)... 

Figure 6 Full multigrid cycle (FMG) see also Figure 4. Instead of starting with an initial guess on the finest level and performing V-cycles from that point, iterations are begun on the coarsest level and the solver progresses toward the finest level. By the time the left side of the finest-level V-cycle has been reached, an excellent initial approximation to the function has been obtained for little computational cost.

Holst, M., R. Kozack, F. Saied and S. Subramaniam. (1994a). Protein electrostatics-Rapid multigrid-based Newton algorithm for solution of the full nonlinear Poisson-Boltzmann equation. J. Biomol. Struct. Dynam. 11 1437-1445. 

The question one might ask is Can we design a coarse-grid problem that possesses the important zero correction at convergence property Here we will discuss the full approximation scheme (FAS) multigrid method, since it is gen-... 

Protein Electrostatics—Rapid Multigrid-Based Newton Algorithm for Solution of the Full Nonlinear Poisson-Boltzmann Equation. 

CGC = coarse grid correction CSD = critical slowing down DH = Debye-Huckel FAS = full approximation scheme FD = finite difference LFT = lattice field theory Ihs = left-hand side MG = multigrid PB = Poi.s.son-Boltzmann PBC = periodic boundary conditioas rhs = right-hand side SOR = successive (or simultaneous) over-relaxation. 

Full Approximation Scheme Nonlinear Multigrid Method... 

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