66   if (nrm >= neP->delta) {  in SNESTR_KSPConverged_Private()
67 …ation early due to exiting trust region, delta=%g, length=%g\n", (double)neP->delta, (double)nrm));  in SNESTR_KSPConverged_Private()
92   if (neP->delta < neP->deltam) {  in SNESTR_Converged_Private()
93 …fo(snes, "Diverged due to too small a trust region %g<%g\n", (double)neP->delta, (double)neP->delt…  in SNESTR_Converged_Private()
490   PetscReal                 rho, fnorm, gnorm = 0.0, xnorm = 0.0, delta, ynorm;  in SNESSolve_NEWTONTR()  local
550   delta      = neP->delta0;  in SNESSolve_NEWTONTR()
551   neP->delta = delta;  in SNESSolve_NEWTONTR()
634     auk = delta / gfnorm_k;  in SNESSolve_NEWTONTR()
636     else tauk = PetscMin(gfnorm * gfnorm * gfnorm_k / (delta * gTBg), 1);  in SNESSolve_NEWTONTR()
648       objmin = -neP->kmdc * gnorm * PetscMin(gnorm / beta_k, delta);  in SNESSolve_NEWTONTR()
652 …tRadius(snes->ksp, neP->fallback == SNES_TR_FALLBACK_NEWTON && neP->norm == NORM_2 ? delta : 0.0));  in SNESSolve_NEWTONTR()
668 …s, "CP evaluated on boundary. delta: %g, ycnorm: %g, gTBg: %g\n", (double)delta, (double)ycnorm, (…  in SNESSolve_NEWTONTR()
673     if (!use_cauchy && (ynorm > delta || ynorm == 0.0)) {  in SNESSolve_NEWTONTR()
679         auk = delta / ynorm;  in SNESSolve_NEWTONTR()
681 …  PetscCall(PetscInfo(snes, "SN evaluated. delta: %g, ynorm: %g\n", (double)delta, (double)ynorm));  in SNESSolve_NEWTONTR()
687 …es, "CP evaluated. delta: %g, ynorm: %g, ycnorm: %g, gTBg: %g\n", (double)delta, (double)ynorm, (d…  in SNESSolve_NEWTONTR()
690           if (gfnorm_k * auk >= delta) { /* first leg: Cauchy point outside of trust region */  in SNESSolve_NEWTONTR()
691             PetscCall(VecAXPBY(Y, delta / gfnorm_k, 0.0, GradF));  in SNESSolve_NEWTONTR()
692 … evaluated (outside region). delta: %g, ynorm: %g, ycnorm: %g\n", (double)delta, (double)ynorm, (d…  in SNESSolve_NEWTONTR()
705             c2 = PetscSqr(ycnorm) - PetscSqr(delta);  in SNESSolve_NEWTONTR()
748 … fkp1=%g, deltaqm=%g, gTy=%g, yTHy=%g, ynormk=%g\n", (double)rho, (double)delta, (double)fk, (doub…  in SNESSolve_NEWTONTR()
751     if (rho < neP->eta2) delta *= neP->t1;                     /* shrink the region */  in SNESSolve_NEWTONTR()
752     else if (rho > neP->eta3 && on_boundary) delta *= neP->t2; /* expand the region */  in SNESSolve_NEWTONTR()
753     delta = PetscMin(delta, neP->deltaM);                      /* but not greater than deltaM */  in SNESSolve_NEWTONTR()
759     neP->delta = delta;  in SNESSolve_NEWTONTR()