lis_solver_set_option(3f)

okay so you just opened the Lis Library Functions manual, and this little cutie is lis_solver_set_option(3f). Buckle up, bestie, we're setting solver options and we're gonna understand every single one 💅

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✨ NAME ✨

lis_solver_set_option — set the options for the solver

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🦋 SYNOPSIS 🦋

subroutine lis_solver_set_option(char *text, LIS_SOLVER *solver, LIS_INTEGER ierr);

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🌸 DESCRIPTION 🌸

Set the options for the solver. That's the whole vibe. You hand it options, it makes the solver do the thing 💖

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🎀 INPUT 🎀

• text — the command line options, literally the words you type to boss the solver around

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💜 OUTPUT 💜

• solver — the solver, all set up and glowing with main character energy

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🔥 NOTE 🔥

Real talk, the table below uses a lil shorthand that you need to get: when you see -i {cg|1}, that means you can write either -i cg or -i 1 (same thing, two fits, pick your fave). And when you see -maxiter [1000], the brackets mean -maxiter defaults to 1,000. iykyk ✨

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👑 OPTIONS 👑

The following options are supported, no cap:

• -i linear solver — pick your linear solver. The following options are supported for linear solver:
  • -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 — pick your preconditioner. The following options are supported for preconditioner:
  • -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)
    • -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, the rest of the crew:

• -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. 📖

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🌈 SEE ALSO 🌈

• lis(3)
• http://www.ssisc.org/lis/

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not me ending on a note but here we are 🫶 this page was a Man Page situation, dated 14 Sep 2017, and its whole name-tag is lis_solver_set_option(3f). periodt 💅✨