Lines Matching refs:stx

10 static PetscErrorCode Tao_mcstep(TaoLineSearch ls, PetscReal *stx, PetscReal *fx, PetscReal *dx, PetscReal *sty, PetscReal *fy, PetscReal *dy, PetscReal *stp, PetscReal *fp, PetscReal *dp);
28   PetscCall(PetscViewerASCIIPrintf(ls->viewer, "stx: %g, fx: %g, dgx: %g\n", (double)mt->stx, (double)mt->fx, (double)mt->dgx));
38   PetscReal         dgx, dgy, dg, dg2, fx, fy, stx, sty, dgtest;
100    stx, fx, dgx - the step, function, and derivative at the best step
105   stx = 0.0;
116       ls->stepmin = PetscMin(stx, sty);
117       ls->stepmax = PetscMax(stx, sty);
119       ls->stepmin = stx;
120       ls->stepmax = ls->step + xtrapf * (ls->step - stx);
129     if (stx != 0 && ((mt->bracket && (ls->step <= ls->stepmin || ls->step >= ls->stepmax)) || (mt->bracket && (ls->stepmax - ls->stepmin <= ls->rtol * ls->stepmax)) || (ls->nfeval + ls->nfgeval >= ls->max_funcs - 1) || mt->infoc == 0))
130       ls->step = stx;
160     mt->stx = stx;
229       fxm  = fx - stx * dgtest;      /* and derivatives */
235       /* if (dgxm * (ls->step - stx) >= 0.0) */
237       PetscCall(Tao_mcstep(ls, &stx, &fxm, &dgxm, &sty, &fym, &dgym, &ls->step, &fm, &dgm));
239       fx  = fxm + stx * dgtest; /* Reset the function and */
245       PetscCall(Tao_mcstep(ls, &stx, &fx, &dgx, &sty, &fy, &dgy, &ls->step, f, &dg));
250       if (PetscAbsReal(sty - stx) >= 0.66 * width1) ls->step = stx + 0.5 * (sty - stx);
252       width  = PetscAbsReal(sty - stx);
311      the parameter stx contains the step with the least function
313      assumed that the derivative at stx is negative in the
316      with endpoints stx and sty.
320      subroutine mcstep(stx,fx,dx,sty,fy,dy,stp,fp,dp,bracket,
325        stx, fx, and dx are variables which specify the step,
328          of the step, that is, dx and stp-stx must have opposite
339          between stx and sty. On output stp is set to the new step.
363 static PetscErrorCode Tao_mcstep(TaoLineSearch ls, PetscReal *stx, PetscReal *fx, PetscReal *dx, PetscReal *sty, PetscReal *fy, PetscReal *dy, PetscReal *stp, PetscReal *fp, PetscReal *dp)
372   PetscCheck(!mtP->bracket || (*stp > PetscMin(*stx, *sty) && *stp < PetscMax(*stx, *sty)), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "bad stp in bracket");
373   PetscCheck(*dx * (*stp - *stx) < 0.0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "dx * (stp-stx) >= 0.0");
382      to stx than the quadratic step, the cubic step is taken,
387     theta      = 3 * (*fx - *fp) / (*stp - *stx) + *dx + *dp;
391     if (*stp < *stx) gamma1 = -gamma1;
396     stpc = *stx + r * (*stp - *stx);
397     stpq = *stx + ((*dx / ((*fx - *fp) / (*stp - *stx) + *dx)) * 0.5) * (*stp - *stx);
399     if (PetscAbsReal(stpc - *stx) < PetscAbsReal(stpq - *stx)) stpf = stpc;
405      step is closer to stx than the quadratic (secant) step,
410     theta      = 3 * (*fx - *fp) / (*stp - *stx) + *dx + *dp;
414     if (*stp > *stx) gamma1 = -gamma1;
418     stpc = *stp + r * (*stx - *stp);
419     stpq = *stp + (*dp / (*dp - *dx)) * (*stx - *stp);
432      closest to stx is taken, else the step farthest away is taken. */
436     theta      = 3 * (*fx - *fp) / (*stp - *stx) + *dx + *dp;
443     if (*stp > *stx) gamma1 = -gamma1;
447     if (r < 0.0 && gamma1 != 0.0) stpc = *stp + r * (*stx - *stp);
448     else if (*stp > *stx) stpc = ls->stepmax;
450     stpq = *stp + (*dp / (*dp - *dx)) * (*stx - *stp);
478     } else if (*stp > *stx) {
494       *sty = *stx;
498     *stx = *stp;
508     if (*sty > *stx) *stp = PetscMin(*stx + 0.66 * (*sty - *stx), *stp);
509     else *stp = PetscMax(*stx + 0.66 * (*sty - *stx), *stp);