SNESNEWTONTRDC#

Newton based nonlinear solver that uses trust-region dogleg method with Cauchy direction

Options Database Keys#

  • -snes_trdc_tol - trust region tolerance

  • -snes_trdc_eta1 - trust region parameter 0.0 <= eta1 <= eta2, rho >= eta1 breaks out of the inner iteration (default: eta1=0.001)

  • -snes_trdc_eta2 - trust region parameter 0.0 <= eta1 <= eta2, rho <= eta2 shrinks the trust region (default: eta2=0.25)

  • -snes_trdc_eta3 - trust region parameter eta3 > eta2, rho >= eta3 expands the trust region (default: eta3=0.75)

  • -snes_trdc_t1 - trust region parameter, shrinking factor of trust region (default: 0.25)

  • -snes_trdc_t2 - trust region parameter, expanding factor of trust region (default: 2.0)

  • -snes_trdc_deltaM - trust region parameter, max size of trust region, \(deltaM*norm2(x)\) (default: 0.5)

  • -snes_trdc_delta0 - trust region parameter, initial size of trust region, \(delta0*norm2(x)\) (default: 0.1)

  • -snes_trdc_auto_scale_max <auto_scale_max> - used with auto_scale_multiphase, caps the maximum auto-scaling factor

  • -snes_trdc_use_cauchy <use_cauchy> - True uses dogleg Cauchy (Steepest Descent direction) step & direction in the trust region algorithm

  • -snes_trdc_auto_scale_multiphase <auto_scale_multiphase> - True turns on auto-scaling for multivariable block matrix for Cauchy and trust region

Note#

See [PHVL21]

References#

PHVL21

Heeho D Park, Glenn E Hammond, Albert J Valocchi, and Tara LaForce. Linear and nonlinear solvers for simulating multiphase flow within large-scale engineered subsurface systems. Advances in Water Resources, 156:104029, 2021.

See Also#

SNES: Nonlinear Solvers, SNESCreate(), SNES, SNESSetType(), SNESNEWTONLS, SNESSetTrustRegionTolerance(), SNESNewtonTRDCPreCheck(), SNESNewtonTRDCGetPreCheck(), SNESNewtonTRDCSetPostCheck(), SNESNewtonTRDCGetPostCheck(), SNESNewtonTRDCGetRhoFlag(), SNESNewtonTRDCSetPreCheck()

Level#

intermediate

Location#

src/snes/impls/ntrdc/ntrdc.c

Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages