lis_solver_set_option(3)

✨ lis_solver_set_option(3) — it's a Lis Library Functions moment ✨

okay bestie, listen, this one lives in the Lis Library Functions section of the manual (that's the man page family, iykyk) and it's literally just "here's how you tell the solver what to do." no cap, it's giving control panel energy 🎛️

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🌸 NAME 🌸

lis_solver_set_option — set the options for the solver 💅

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🦋 SYNOPSIS 🦋

#include "lis.h"

LIS_INT lis_solver_set_option(char *text, LIS_SOLVER *solver);

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💖 DESCRIPTION 💖

It sets the options for the solver. That's it, that's the whole vibe — you hand it some text full of flags and it makes the solver act accordingly. iconic behavior honestly ✨

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🎀 INPUT 🎀

• text — The command line options 🫶

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🌈 OUTPUT 🌈

• solver — The solver 👑

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⭐ EXIT STATUS ⭐

Here's what you can get back, bestie:

• 0 — The process is normally terminated ✅
• unspecified — An error occurred 😭

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💀 NOTE 💀

So the option tables below have a little shorthand you need to know or you WILL be confused, and not in the cute way. When you see -i {cg|1}, that means you can write either -i cg or -i 1 — same thing, two names. And when you see brackets like -maxiter [1000], the number inside is the default, so -maxiter defaults to 1,000. periodt 💅

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🔥 OPTIONS 🔥

The following options are supported:

• -i linear solver — pick your linear solver, this is the main character choice fr. Here's everything supported for it:
  • -i {cg|1} — CG
  • -i {bicg|2} — BiCG
  • -i {cgs|3} — CGS
  • -i {bicgstab|4} — BiCGSTAB
  • -i {bicgstabl|5} — BiCGSTAB(l)
    • -ell [2] — The degree l
  • -i {gpbicg|6} — GPBiCG
  • -i {tfqmr|7} — TFQMR
  • -i {orthomin|8} — Orthomin(m)
    • -restart [40] — The restart value m
  • -i {gmres|9} — GMRES(m)
    • -restart [40] — The restart value m
  • -i {jacobi|10} — Jacobi
  • -i {gs|11} — Gauss-Seidel
  • -i {sor|12} — SOR
    • -omega [1.9] — The relaxation coefficient omega (0<omega<2)
  • -i {bicgsafe|13} — BiCGSafe
  • -i {cr|14} — CR
  • -i {bicr|15} — BiCR
  • -i {crs|16} — CRS
  • -i {bicrstab|17} — BiCRSTAB
  • -i {gpbicr|18} — GPBiCR
  • -i {bicrsafe|19} — BiCRSafe
  • -i {fgmres|20} — FGMRES(m)
    • -restart [40] — The restart value m
  • -i {idrs|21} — IDR(s)
    • -irestart [2] — The restart value s
  • -i {idr1|22} — IDR(1)
  • -i {minres|23} — MINRES
  • -i {cocg|24} — COCG
  • -i {cocr|25} — COCR
• -p preconditioner — now for the preconditioner, aka the glow-up your matrix gets before the solver looks at it 💖. The following options are supported:
  • -p {none|0} — None
  • -p {jacobi|1} — Jacobi
  • -p {ilu|2} — ILU(k)
    • -ilu_fill [0] — The fill level k
  • -p {ssor|3} — SSOR
    • -ssor_omega [1.0] — The relaxation coefficient omega (0<omega<2)
  • -p {hybrid|4} — Hybrid
    • -hybrid_i [sor] — The linear solver
    • -hybrid_maxiter [25] — The maximum number of iterations
    • -hybrid_tol [1.0e-3] — The convergence criterion
    • -hybrid_omega [1.5] — The relaxation coefficient omega of the SOR (0<omega<2)
    • -hybrid_ell [2] — The degree l of the BiCGSTAB(l)
    • -hybrid_restart [40] — The restart values of the GMRES and Orthomin
  • -p {is|5} — I+S
    • -is_alpha [1.0] — The parameter alpha of I+alpha*S(m)
    • -is_m [3] — The parameter m of I+alpha*S(m)
  • -p {sainv|6} — SAINV
    • -sainv_drop [0.05] — The drop criterion
  • -p {saamg|7} — SA-AMG
    • -saamg_unsym [false] — Select the unsymmetric version (The matrix structure must be symmetric) ⚠️ yes bestie, read that parenthetical, the structure has to be symmetric
    • -saamg_theta [0.05|0.12] — The drop criterion
  • -p {iluc|8} — Crout ILU
    • -iluc_drop [0.05] — The drop criterion
    • -iluc_rate [5.0] — The ration of maximum fill-in
  • -p {ilut|9} — ILUT
    • -ilut_drop [0.05] — The drop criterion
    • -ilut_rate [5.0] — The ration of maximum fill-in
  • -adds true — Additive Schwarz
    • -adds_iter [1] — The number of iteration

👑 Other Options 👑

• -maxiter [1000] — The maximum number of iterations
• -tol [1.0e-12] — The convergence criterion
• -print [0] — The display of the residual
  • -print {none|0} — None
  • -print {mem|1} — Save the residual history
  • -print {out|2} — Display the residual history
  • -print {all|3} — Save the residual history and display it on the screen
• -scale [0] — The scaling
  • -scale {none|0} — No scaling
  • -scale {jacobi|1} — The Jacobi scaling
  • -scale {symm_diag|2} — The diagonal scaling
• -initx_zeros [true] — The behavior of the initial vector x_0
  • -initx_zero {false|0} — Given values
  • -initx_zero {true|1} — All values are set to 0
• -omp_num_threads [t] — The number of threads (t represents the maximum number of threads)
• -storage [0] — The matrix storage format
• -storage_block [2] — The block size of the BSR and BSC formats
• -f [0] — The precision of the linear solver
  • -f {double|0} — Double precision
  • -f {quad|1} — Double-double (quadruple) precision

See Lis User Guide for full description. fr fr, go read it if you want the whole lore 📖

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🧚 SEE ALSO 🧚

• lis(3)
• http://www.ssisc.org/lis/

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and that's the whole page bestie 💜 this cutie was served up by the Man Page crew on 14 Sep 2017, and its official handle is lis_solver_set_option(3) — go forth and set those options, you absolute legend 👑✨