These strings are accepted by gauss_jacobi_rule (Fortran). C and Python expose
the single-image set via gauss_jacobi_rule_c / the extension (rec, gw, algo665, algo665_dc, sturm,
glr, bogaert, auto).
Use Fortran + cafrun for multi-image *_caf.
| String | Meaning | Multi-image |
|---|---|---|
(omit) / "" / "auto" |
select_method_auto |
Picks *_caf if num_images()>1 |
rec |
Hale–Townsend-style Newton | — |
rec_caf |
Same; CAF over root index | yes |
gw / gw_caf |
Golub–Welsch + dsteqr |
one rule serial |
algo665 / algo665_caf |
GW + imtqlx |
one rule serial |
algo665_dc |
Cuppen D&C + imtqlx leaves |
— |
algo665_dc_caf |
D&C with CAF hooks | yes |
sturm / sturm_caf |
Sturm bisection + inv. iter. | eig index (CAF) |
glr |
Prüfer phase-by-π + Newton | sequential |
glr_caf |
Independent k-th starters + Newton | root index (CAF) |
bogaert |
Legendre asymptotics | — |
bogaert_caf |
Same; CAF over half-node index | yes |
bogaert / bogaert_caf: α=β=0 and n≥21 only.
Source of truth: src/GaussJacobiQuad.f90 select case, src/gjp_auto.f90, and interfaces/CInterface/GaussJacobiQuadCInterp.h
(C subset).