# Krylov Solvers

group KrylovSolvers

A basic interface for Krylov solvers.

These solvers support many of the matrix/vector storage schemes in hypre. They should be used in conjunction with the storage-specific interfaces, particularly the specific Create() and Destroy() functions.

Krylov Solvers

typedef HYPRE_Int (*HYPRE_PtrToModifyPCFcn)(HYPRE_Solver, HYPRE_Int, HYPRE_Real)
HYPRE_MODIFYPC

PCG Solver

HYPRE_Int HYPRE_PCGSetup(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Prepare to solve the system.

The coefficient data in b and x is ignored here, but information about the layout of the data may be used.

HYPRE_Int HYPRE_PCGSolve(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Solve the system.

HYPRE_Int HYPRE_PCGSetTol(HYPRE_Solver solver, HYPRE_Real tol)

(Optional) Set the relative convergence tolerance.

HYPRE_Int HYPRE_PCGSetAbsoluteTol(HYPRE_Solver solver, HYPRE_Real a_tol)

(Optional) Set the absolute convergence tolerance (default is 0).

If one desires the convergence test to check the absolute convergence tolerance only, then set the relative convergence tolerance to 0.0. (The default convergence test is $$<C*r,r> \leq$$ max(relative $$\_$$tolerance $$^{2} \ast <C*b, b>$$, absolute $$\_$$tolerance $$^2$$).)

HYPRE_Int HYPRE_PCGSetResidualTol(HYPRE_Solver solver, HYPRE_Real rtol)

(Optional) Set a residual-based convergence tolerance which checks if $$\|r_{old}-r_{new}\| < rtol \|b\|$$.

This is useful when trying to converge to very low relative and/or absolute tolerances, in order to bail-out before roundoff errors affect the approximation.

HYPRE_Int HYPRE_PCGSetAbsoluteTolFactor(HYPRE_Solver solver, HYPRE_Real abstolf)
HYPRE_Int HYPRE_PCGSetConvergenceFactorTol(HYPRE_Solver solver, HYPRE_Real cf_tol)
HYPRE_Int HYPRE_PCGSetStopCrit(HYPRE_Solver solver, HYPRE_Int stop_crit)
HYPRE_Int HYPRE_PCGSetMaxIter(HYPRE_Solver solver, HYPRE_Int max_iter)

(Optional) Set maximum number of iterations.

HYPRE_Int HYPRE_PCGSetTwoNorm(HYPRE_Solver solver, HYPRE_Int two_norm)

(Optional) Use the two-norm in stopping criteria.

HYPRE_Int HYPRE_PCGSetRelChange(HYPRE_Solver solver, HYPRE_Int rel_change)

(Optional) Additionally require that the relative difference in successive iterates be small.

HYPRE_Int HYPRE_PCGSetRecomputeResidual(HYPRE_Solver solver, HYPRE_Int recompute_residual)

(Optional) Recompute the residual at the end to double-check convergence.

HYPRE_Int HYPRE_PCGSetRecomputeResidualP(HYPRE_Solver solver, HYPRE_Int recompute_residual_p)

(Optional) Periodically recompute the residual while iterating.

HYPRE_Int HYPRE_PCGSetFlex(HYPRE_Solver solver, HYPRE_Int flex)

(Optional) Setting this to 1 allows use of Polak-Ribiere Method (flexible) this incrceases robustness, but adds an additional dot product per iteration

HYPRE_Int HYPRE_PCGSetSkipBreak(HYPRE_Solver solver, HYPRE_Int skip_break)

(Optional) Skips subnormal alpha, gamma and iprod values in CG.

If set to 0 (default): will break if values are below HYPRE_REAL_MIN If set to 1: will break if values are below HYPRE_REAL_TRUE_MIN (requires C11 minimal or will check to HYPRE_REAL_MIN) If set to 2: will break if values are <= 0. If set to 3 or larger: will not break at all

HYPRE_Int HYPRE_PCGSetPrecond(HYPRE_Solver solver, HYPRE_PtrToSolverFcn precond, HYPRE_PtrToSolverFcn precond_setup, HYPRE_Solver precond_solver)

(Optional) Set the preconditioner to use.

HYPRE_Int HYPRE_PCGSetPreconditioner(HYPRE_Solver solver, HYPRE_Solver precond)

(Optional) Set the preconditioner to use in a generic fashion.

This function does not require explicit input of the setup and solve pointers of the preconditioner object. Instead, it automatically extracts this information from the aforementioned object.

HYPRE_Int HYPRE_PCGSetLogging(HYPRE_Solver solver, HYPRE_Int logging)

(Optional) Set the amount of logging to do.

HYPRE_Int HYPRE_PCGSetPrintLevel(HYPRE_Solver solver, HYPRE_Int level)

(Optional) Set the amount of printing to do to the screen.

HYPRE_Int HYPRE_PCGGetNumIterations(HYPRE_Solver solver, HYPRE_Int *num_iterations)

Return the number of iterations taken.

HYPRE_Int HYPRE_PCGGetFinalRelativeResidualNorm(HYPRE_Solver solver, HYPRE_Real *norm)

Return the norm of the final relative residual.

HYPRE_Int HYPRE_PCGGetResidual(HYPRE_Solver solver, void *residual)

Return the residual.

HYPRE_Int HYPRE_PCGGetTol(HYPRE_Solver solver, HYPRE_Real *tol)
HYPRE_Int HYPRE_PCGGetResidualTol(HYPRE_Solver solver, HYPRE_Real *rtol)
HYPRE_Int HYPRE_PCGGetAbsoluteTolFactor(HYPRE_Solver solver, HYPRE_Real *abstolf)
HYPRE_Int HYPRE_PCGGetConvergenceFactorTol(HYPRE_Solver solver, HYPRE_Real *cf_tol)
HYPRE_Int HYPRE_PCGGetStopCrit(HYPRE_Solver solver, HYPRE_Int *stop_crit)
HYPRE_Int HYPRE_PCGGetMaxIter(HYPRE_Solver solver, HYPRE_Int *max_iter)
HYPRE_Int HYPRE_PCGGetTwoNorm(HYPRE_Solver solver, HYPRE_Int *two_norm)
HYPRE_Int HYPRE_PCGGetRelChange(HYPRE_Solver solver, HYPRE_Int *rel_change)
HYPRE_Int HYPRE_PCGGetSkipBreak(HYPRE_Solver solver, HYPRE_Int *skip_break)
HYPRE_Int HYPRE_PCGGetFlex(HYPRE_Solver solver, HYPRE_Int *flex)
HYPRE_Int HYPRE_PCGGetPrecond(HYPRE_Solver solver, HYPRE_Solver *precond_data_ptr)
HYPRE_Int HYPRE_PCGGetLogging(HYPRE_Solver solver, HYPRE_Int *level)
HYPRE_Int HYPRE_PCGGetPrintLevel(HYPRE_Solver solver, HYPRE_Int *level)
HYPRE_Int HYPRE_PCGGetConverged(HYPRE_Solver solver, HYPRE_Int *converged)

GMRES Solver

HYPRE_Int HYPRE_GMRESSetup(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Prepare to solve the system.

The coefficient data in b and x is ignored here, but information about the layout of the data may be used.

HYPRE_Int HYPRE_GMRESSolve(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Solve the system.

HYPRE_Int HYPRE_GMRESSetTol(HYPRE_Solver solver, HYPRE_Real tol)

(Optional) Set the relative convergence tolerance.

HYPRE_Int HYPRE_GMRESSetAbsoluteTol(HYPRE_Solver solver, HYPRE_Real a_tol)

(Optional) Set the absolute convergence tolerance (default is 0).

If one desires the convergence test to check the absolute convergence tolerance only, then set the relative convergence tolerance to 0.0. (The convergence test is $$\|r\| \leq$$ max(relative $$\_$$tolerance $$\ast \|b\|$$, absolute $$\_$$tolerance).)

HYPRE_Int HYPRE_GMRESSetConvergenceFactorTol(HYPRE_Solver solver, HYPRE_Real cf_tol)
HYPRE_Int HYPRE_GMRESSetStopCrit(HYPRE_Solver solver, HYPRE_Int stop_crit)
HYPRE_Int HYPRE_GMRESSetMinIter(HYPRE_Solver solver, HYPRE_Int min_iter)
HYPRE_Int HYPRE_GMRESSetMaxIter(HYPRE_Solver solver, HYPRE_Int max_iter)

(Optional) Set maximum number of iterations.

HYPRE_Int HYPRE_GMRESSetKDim(HYPRE_Solver solver, HYPRE_Int k_dim)

(Optional) Set the maximum size of the Krylov space.

HYPRE_Int HYPRE_GMRESSetRelChange(HYPRE_Solver solver, HYPRE_Int rel_change)

(Optional) Additionally require that the relative difference in successive iterates be small.

HYPRE_Int HYPRE_GMRESSetSkipRealResidualCheck(HYPRE_Solver solver, HYPRE_Int skip_real_r_check)

(Optional) By default, hypre checks for convergence by evaluating the actual residual before returnig from GMRES (with restart if the true residual does not indicate convergence).

This option allows users to skip the evaluation and the check of the actual residual for badly conditioned problems where restart is not expected to be beneficial.

HYPRE_Int HYPRE_GMRESSetPrecond(HYPRE_Solver solver, HYPRE_PtrToSolverFcn precond, HYPRE_PtrToSolverFcn precond_setup, HYPRE_Solver precond_solver)

(Optional) Set the preconditioner to use.

HYPRE_Int HYPRE_GMRESSetLogging(HYPRE_Solver solver, HYPRE_Int logging)

(Optional) Set the amount of logging to do.

HYPRE_Int HYPRE_GMRESSetPrintLevel(HYPRE_Solver solver, HYPRE_Int level)

(Optional) Set the amount of printing to do to the screen.

HYPRE_Int HYPRE_GMRESGetNumIterations(HYPRE_Solver solver, HYPRE_Int *num_iterations)

Return the number of iterations taken.

HYPRE_Int HYPRE_GMRESGetFinalRelativeResidualNorm(HYPRE_Solver solver, HYPRE_Real *norm)

Return the norm of the final relative residual.

HYPRE_Int HYPRE_GMRESGetResidual(HYPRE_Solver solver, void *residual)

Return the residual.

HYPRE_Int HYPRE_GMRESGetSkipRealResidualCheck(HYPRE_Solver solver, HYPRE_Int *skip_real_r_check)
HYPRE_Int HYPRE_GMRESGetTol(HYPRE_Solver solver, HYPRE_Real *tol)
HYPRE_Int HYPRE_GMRESGetAbsoluteTol(HYPRE_Solver solver, HYPRE_Real *tol)
HYPRE_Int HYPRE_GMRESGetConvergenceFactorTol(HYPRE_Solver solver, HYPRE_Real *cf_tol)
HYPRE_Int HYPRE_GMRESGetStopCrit(HYPRE_Solver solver, HYPRE_Int *stop_crit)
HYPRE_Int HYPRE_GMRESGetMinIter(HYPRE_Solver solver, HYPRE_Int *min_iter)
HYPRE_Int HYPRE_GMRESGetMaxIter(HYPRE_Solver solver, HYPRE_Int *max_iter)
HYPRE_Int HYPRE_GMRESGetKDim(HYPRE_Solver solver, HYPRE_Int *k_dim)
HYPRE_Int HYPRE_GMRESGetRelChange(HYPRE_Solver solver, HYPRE_Int *rel_change)
HYPRE_Int HYPRE_GMRESGetPrecond(HYPRE_Solver solver, HYPRE_Solver *precond_data_ptr)
HYPRE_Int HYPRE_GMRESGetLogging(HYPRE_Solver solver, HYPRE_Int *level)
HYPRE_Int HYPRE_GMRESGetPrintLevel(HYPRE_Solver solver, HYPRE_Int *level)
HYPRE_Int HYPRE_GMRESGetConverged(HYPRE_Solver solver, HYPRE_Int *converged)

FlexGMRES Solver

HYPRE_Int HYPRE_FlexGMRESSetup(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Prepare to solve the system.

The coefficient data in b and x is ignored here, but information about the layout of the data may be used.

HYPRE_Int HYPRE_FlexGMRESSolve(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Solve the system.

HYPRE_Int HYPRE_FlexGMRESSetTol(HYPRE_Solver solver, HYPRE_Real tol)

(Optional) Set the convergence tolerance.

HYPRE_Int HYPRE_FlexGMRESSetAbsoluteTol(HYPRE_Solver solver, HYPRE_Real a_tol)

(Optional) Set the absolute convergence tolerance (default is 0).

If one desires the convergence test to check the absolute convergence tolerance only, then set the relative convergence tolerance to 0.0. (The convergence test is $$\|r\| \leq$$ max(relative $$\_$$tolerance $$\ast \|b\|$$, absolute $$\_$$tolerance).)

HYPRE_Int HYPRE_FlexGMRESSetConvergenceFactorTol(HYPRE_Solver solver, HYPRE_Real cf_tol)
HYPRE_Int HYPRE_FlexGMRESSetMinIter(HYPRE_Solver solver, HYPRE_Int min_iter)
HYPRE_Int HYPRE_FlexGMRESSetMaxIter(HYPRE_Solver solver, HYPRE_Int max_iter)

(Optional) Set maximum number of iterations.

HYPRE_Int HYPRE_FlexGMRESSetKDim(HYPRE_Solver solver, HYPRE_Int k_dim)

(Optional) Set the maximum size of the Krylov space.

HYPRE_Int HYPRE_FlexGMRESSetPrecond(HYPRE_Solver solver, HYPRE_PtrToSolverFcn precond, HYPRE_PtrToSolverFcn precond_setup, HYPRE_Solver precond_solver)

(Optional) Set the preconditioner to use.

HYPRE_Int HYPRE_FlexGMRESSetLogging(HYPRE_Solver solver, HYPRE_Int logging)

(Optional) Set the amount of logging to do.

HYPRE_Int HYPRE_FlexGMRESSetPrintLevel(HYPRE_Solver solver, HYPRE_Int level)

(Optional) Set the amount of printing to do to the screen.

HYPRE_Int HYPRE_FlexGMRESGetNumIterations(HYPRE_Solver solver, HYPRE_Int *num_iterations)

Return the number of iterations taken.

HYPRE_Int HYPRE_FlexGMRESGetFinalRelativeResidualNorm(HYPRE_Solver solver, HYPRE_Real *norm)

Return the norm of the final relative residual.

HYPRE_Int HYPRE_FlexGMRESGetResidual(HYPRE_Solver solver, void *residual)

Return the residual.

HYPRE_Int HYPRE_FlexGMRESGetTol(HYPRE_Solver solver, HYPRE_Real *tol)
HYPRE_Int HYPRE_FlexGMRESGetConvergenceFactorTol(HYPRE_Solver solver, HYPRE_Real *cf_tol)
HYPRE_Int HYPRE_FlexGMRESGetStopCrit(HYPRE_Solver solver, HYPRE_Int *stop_crit)
HYPRE_Int HYPRE_FlexGMRESGetMinIter(HYPRE_Solver solver, HYPRE_Int *min_iter)
HYPRE_Int HYPRE_FlexGMRESGetMaxIter(HYPRE_Solver solver, HYPRE_Int *max_iter)
HYPRE_Int HYPRE_FlexGMRESGetKDim(HYPRE_Solver solver, HYPRE_Int *k_dim)
HYPRE_Int HYPRE_FlexGMRESGetPrecond(HYPRE_Solver solver, HYPRE_Solver *precond_data_ptr)
HYPRE_Int HYPRE_FlexGMRESGetLogging(HYPRE_Solver solver, HYPRE_Int *level)
HYPRE_Int HYPRE_FlexGMRESGetPrintLevel(HYPRE_Solver solver, HYPRE_Int *level)
HYPRE_Int HYPRE_FlexGMRESGetConverged(HYPRE_Solver solver, HYPRE_Int *converged)
HYPRE_Int HYPRE_FlexGMRESSetModifyPC(HYPRE_Solver solver, HYPRE_PtrToModifyPCFcn modify_pc)

(Optional) Set a user-defined function to modify solve-time preconditioner attributes.

LGMRES Solver

HYPRE_Int HYPRE_LGMRESSetup(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Prepare to solve the system.

The coefficient data in b and x is ignored here, but information about the layout of the data may be used.

HYPRE_Int HYPRE_LGMRESSolve(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Solve the system.

Details on LGMRES may be found in A. H. Baker, E.R. Jessup, and T.A. Manteuffel, “A technique for accelerating the

convergence of restarted GMRES.” SIAM Journal on Matrix Analysis and Applications, 26 (2005), pp. 962-984. LGMRES(m,k) in the paper corresponds to LGMRES(Kdim+AugDim, AugDim).

HYPRE_Int HYPRE_LGMRESSetTol(HYPRE_Solver solver, HYPRE_Real tol)

(Optional) Set the convergence tolerance.

HYPRE_Int HYPRE_LGMRESSetAbsoluteTol(HYPRE_Solver solver, HYPRE_Real a_tol)

(Optional) Set the absolute convergence tolerance (default is 0).

If one desires the convergence test to check the absolute convergence tolerance only, then set the relative convergence tolerance to 0.0. (The convergence test is $$\|r\| \leq$$ max(relative $$\_$$tolerance $$\ast \|b\|$$, absolute $$\_$$tolerance).)

HYPRE_Int HYPRE_LGMRESSetConvergenceFactorTol(HYPRE_Solver solver, HYPRE_Real cf_tol)
HYPRE_Int HYPRE_LGMRESSetMinIter(HYPRE_Solver solver, HYPRE_Int min_iter)
HYPRE_Int HYPRE_LGMRESSetMaxIter(HYPRE_Solver solver, HYPRE_Int max_iter)

(Optional) Set maximum number of iterations.

HYPRE_Int HYPRE_LGMRESSetKDim(HYPRE_Solver solver, HYPRE_Int k_dim)

(Optional) Set the maximum size of the approximation space (includes the augmentation vectors).

HYPRE_Int HYPRE_LGMRESSetAugDim(HYPRE_Solver solver, HYPRE_Int aug_dim)

(Optional) Set the number of augmentation vectors (default: 2).

HYPRE_Int HYPRE_LGMRESSetPrecond(HYPRE_Solver solver, HYPRE_PtrToSolverFcn precond, HYPRE_PtrToSolverFcn precond_setup, HYPRE_Solver precond_solver)

(Optional) Set the preconditioner to use.

HYPRE_Int HYPRE_LGMRESSetLogging(HYPRE_Solver solver, HYPRE_Int logging)

(Optional) Set the amount of logging to do.

HYPRE_Int HYPRE_LGMRESSetPrintLevel(HYPRE_Solver solver, HYPRE_Int level)

(Optional) Set the amount of printing to do to the screen.

HYPRE_Int HYPRE_LGMRESGetNumIterations(HYPRE_Solver solver, HYPRE_Int *num_iterations)

Return the number of iterations taken.

HYPRE_Int HYPRE_LGMRESGetFinalRelativeResidualNorm(HYPRE_Solver solver, HYPRE_Real *norm)

Return the norm of the final relative residual.

HYPRE_Int HYPRE_LGMRESGetResidual(HYPRE_Solver solver, void *residual)

Return the residual.

HYPRE_Int HYPRE_LGMRESGetTol(HYPRE_Solver solver, HYPRE_Real *tol)
HYPRE_Int HYPRE_LGMRESGetConvergenceFactorTol(HYPRE_Solver solver, HYPRE_Real *cf_tol)
HYPRE_Int HYPRE_LGMRESGetStopCrit(HYPRE_Solver solver, HYPRE_Int *stop_crit)
HYPRE_Int HYPRE_LGMRESGetMinIter(HYPRE_Solver solver, HYPRE_Int *min_iter)
HYPRE_Int HYPRE_LGMRESGetMaxIter(HYPRE_Solver solver, HYPRE_Int *max_iter)
HYPRE_Int HYPRE_LGMRESGetKDim(HYPRE_Solver solver, HYPRE_Int *k_dim)
HYPRE_Int HYPRE_LGMRESGetAugDim(HYPRE_Solver solver, HYPRE_Int *k_dim)
HYPRE_Int HYPRE_LGMRESGetPrecond(HYPRE_Solver solver, HYPRE_Solver *precond_data_ptr)
HYPRE_Int HYPRE_LGMRESGetLogging(HYPRE_Solver solver, HYPRE_Int *level)
HYPRE_Int HYPRE_LGMRESGetPrintLevel(HYPRE_Solver solver, HYPRE_Int *level)
HYPRE_Int HYPRE_LGMRESGetConverged(HYPRE_Solver solver, HYPRE_Int *converged)

COGMRES Solver

HYPRE_Int HYPRE_COGMRESSetup(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Prepare to solve the system.

The coefficient data in b and x is ignored here, but information about the layout of the data may be used.

HYPRE_Int HYPRE_COGMRESSolve(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Solve the system.

HYPRE_Int HYPRE_COGMRESSetTol(HYPRE_Solver solver, HYPRE_Real tol)

(Optional) Set the convergence tolerance.

HYPRE_Int HYPRE_COGMRESSetAbsoluteTol(HYPRE_Solver solver, HYPRE_Real a_tol)

(Optional) Set the absolute convergence tolerance (default is 0).

If one desires the convergence test to check the absolute convergence tolerance only, then set the relative convergence tolerance to 0.0. (The convergence test is $$\|r\| \leq$$ max(relative $$\_$$tolerance $$\ast \|b\|$$, absolute $$\_$$tolerance).)

HYPRE_Int HYPRE_COGMRESSetConvergenceFactorTol(HYPRE_Solver solver, HYPRE_Real cf_tol)
HYPRE_Int HYPRE_COGMRESSetMinIter(HYPRE_Solver solver, HYPRE_Int min_iter)
HYPRE_Int HYPRE_COGMRESSetMaxIter(HYPRE_Solver solver, HYPRE_Int max_iter)

(Optional) Set maximum number of iterations.

HYPRE_Int HYPRE_COGMRESSetKDim(HYPRE_Solver solver, HYPRE_Int k_dim)

(Optional) Set the maximum size of the Krylov space.

HYPRE_Int HYPRE_COGMRESSetUnroll(HYPRE_Solver solver, HYPRE_Int unroll)

(Optional) Set number of unrolling in mass funcyions in COGMRES Can be 4 or 8.

Default: no unrolling.

HYPRE_Int HYPRE_COGMRESSetCGS(HYPRE_Solver solver, HYPRE_Int cgs)

(Optional) Set the number of orthogonalizations in COGMRES (at most 2).

HYPRE_Int HYPRE_COGMRESSetPrecond(HYPRE_Solver solver, HYPRE_PtrToSolverFcn precond, HYPRE_PtrToSolverFcn precond_setup, HYPRE_Solver precond_solver)

(Optional) Set the preconditioner to use.

HYPRE_Int HYPRE_COGMRESSetLogging(HYPRE_Solver solver, HYPRE_Int logging)

(Optional) Set the amount of logging to do.

HYPRE_Int HYPRE_COGMRESSetPrintLevel(HYPRE_Solver solver, HYPRE_Int level)

(Optional) Set the amount of printing to do to the screen.

HYPRE_Int HYPRE_COGMRESGetNumIterations(HYPRE_Solver solver, HYPRE_Int *num_iterations)

Return the number of iterations taken.

HYPRE_Int HYPRE_COGMRESGetFinalRelativeResidualNorm(HYPRE_Solver solver, HYPRE_Real *norm)

Return the norm of the final relative residual.

HYPRE_Int HYPRE_COGMRESGetResidual(HYPRE_Solver solver, void *residual)

Return the residual.

HYPRE_Int HYPRE_COGMRESGetTol(HYPRE_Solver solver, HYPRE_Real *tol)
HYPRE_Int HYPRE_COGMRESGetConvergenceFactorTol(HYPRE_Solver solver, HYPRE_Real *cf_tol)
HYPRE_Int HYPRE_COGMRESGetMinIter(HYPRE_Solver solver, HYPRE_Int *min_iter)
HYPRE_Int HYPRE_COGMRESGetMaxIter(HYPRE_Solver solver, HYPRE_Int *max_iter)
HYPRE_Int HYPRE_COGMRESGetKDim(HYPRE_Solver solver, HYPRE_Int *k_dim)
HYPRE_Int HYPRE_COGMRESGetUnroll(HYPRE_Solver solver, HYPRE_Int *unroll)
HYPRE_Int HYPRE_COGMRESGetCGS(HYPRE_Solver solver, HYPRE_Int *cgs)
HYPRE_Int HYPRE_COGMRESGetPrecond(HYPRE_Solver solver, HYPRE_Solver *precond_data_ptr)
HYPRE_Int HYPRE_COGMRESGetLogging(HYPRE_Solver solver, HYPRE_Int *level)
HYPRE_Int HYPRE_COGMRESGetPrintLevel(HYPRE_Solver solver, HYPRE_Int *level)
HYPRE_Int HYPRE_COGMRESGetConverged(HYPRE_Solver solver, HYPRE_Int *converged)
HYPRE_Int HYPRE_COGMRESSetModifyPC(HYPRE_Solver solver, HYPRE_PtrToModifyPCFcn modify_pc)

(Optional) Set a user-defined function to modify solve-time preconditioner attributes.

BiCGSTAB Solver

HYPRE_Int HYPRE_BiCGSTABDestroy(HYPRE_Solver solver)
HYPRE_Int HYPRE_BiCGSTABSetup(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Prepare to solve the system.

The coefficient data in b and x is ignored here, but information about the layout of the data may be used.

HYPRE_Int HYPRE_BiCGSTABSolve(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Solve the system.

HYPRE_Int HYPRE_BiCGSTABSetTol(HYPRE_Solver solver, HYPRE_Real tol)

(Optional) Set the convergence tolerance.

HYPRE_Int HYPRE_BiCGSTABSetAbsoluteTol(HYPRE_Solver solver, HYPRE_Real a_tol)

(Optional) Set the absolute convergence tolerance (default is 0).

If one desires the convergence test to check the absolute convergence tolerance only, then set the relative convergence tolerance to 0.0. (The convergence test is $$\|r\| \leq$$ max(relative $$\_$$tolerance $$\ast \|b\|$$, absolute $$\_$$tolerance).)

HYPRE_Int HYPRE_BiCGSTABSetConvergenceFactorTol(HYPRE_Solver solver, HYPRE_Real cf_tol)
HYPRE_Int HYPRE_BiCGSTABSetStopCrit(HYPRE_Solver solver, HYPRE_Int stop_crit)
HYPRE_Int HYPRE_BiCGSTABSetMinIter(HYPRE_Solver solver, HYPRE_Int min_iter)
HYPRE_Int HYPRE_BiCGSTABSetMaxIter(HYPRE_Solver solver, HYPRE_Int max_iter)

(Optional) Set maximum number of iterations.

HYPRE_Int HYPRE_BiCGSTABSetPrecond(HYPRE_Solver solver, HYPRE_PtrToSolverFcn precond, HYPRE_PtrToSolverFcn precond_setup, HYPRE_Solver precond_solver)

(Optional) Set the preconditioner to use.

HYPRE_Int HYPRE_BiCGSTABSetLogging(HYPRE_Solver solver, HYPRE_Int logging)

(Optional) Set the amount of logging to do.

HYPRE_Int HYPRE_BiCGSTABSetPrintLevel(HYPRE_Solver solver, HYPRE_Int level)

(Optional) Set the amount of printing to do to the screen.

HYPRE_Int HYPRE_BiCGSTABGetNumIterations(HYPRE_Solver solver, HYPRE_Int *num_iterations)

Return the number of iterations taken.

HYPRE_Int HYPRE_BiCGSTABGetFinalRelativeResidualNorm(HYPRE_Solver solver, HYPRE_Real *norm)

Return the norm of the final relative residual.

HYPRE_Int HYPRE_BiCGSTABGetResidual(HYPRE_Solver solver, void *residual)

Return the residual.

HYPRE_Int HYPRE_BiCGSTABGetPrecond(HYPRE_Solver solver, HYPRE_Solver *precond_data_ptr)

CGNR Solver

HYPRE_Int HYPRE_CGNRDestroy(HYPRE_Solver solver)
HYPRE_Int HYPRE_CGNRSetup(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Prepare to solve the system.

The coefficient data in b and x is ignored here, but information about the layout of the data may be used.

HYPRE_Int HYPRE_CGNRSolve(HYPRE_Solver solver, HYPRE_Matrix A, HYPRE_Vector b, HYPRE_Vector x)

Solve the system.

HYPRE_Int HYPRE_CGNRSetTol(HYPRE_Solver solver, HYPRE_Real tol)

(Optional) Set the convergence tolerance.

HYPRE_Int HYPRE_CGNRSetStopCrit(HYPRE_Solver solver, HYPRE_Int stop_crit)
HYPRE_Int HYPRE_CGNRSetMinIter(HYPRE_Solver solver, HYPRE_Int min_iter)
HYPRE_Int HYPRE_CGNRSetMaxIter(HYPRE_Solver solver, HYPRE_Int max_iter)

(Optional) Set maximum number of iterations.

HYPRE_Int HYPRE_CGNRSetPrecond(HYPRE_Solver solver, HYPRE_PtrToSolverFcn precond, HYPRE_PtrToSolverFcn precondT, HYPRE_PtrToSolverFcn precond_setup, HYPRE_Solver precond_solver)

(Optional) Set the preconditioner to use.

Note that the only preconditioner available in hypre for use with CGNR is currently BoomerAMG. It requires to use Jacobi as a smoother without CF smoothing, i.e. relax_type needs to be set to 0 or 7 and relax_order needs to be set to 0 by the user, since these are not default values. It can be used with a relaxation weight for Jacobi, which can significantly improve convergence.

HYPRE_Int HYPRE_CGNRSetLogging(HYPRE_Solver solver, HYPRE_Int logging)

(Optional) Set the amount of logging to do.

HYPRE_Int HYPRE_CGNRGetNumIterations(HYPRE_Solver solver, HYPRE_Int *num_iterations)

Return the number of iterations taken.

HYPRE_Int HYPRE_CGNRGetFinalRelativeResidualNorm(HYPRE_Solver solver, HYPRE_Real *norm)

Return the norm of the final relative residual.

HYPRE_Int HYPRE_CGNRGetPrecond(HYPRE_Solver solver, HYPRE_Solver *precond_data_ptr)