static int region4_df(const gsl_vector *x, void *user_data, gsl_matrix *J){
#define D ((Solver2Data *)user_data)
SteamState S = freesteam_region4_set_Tx(gsl_vector_get(x,0),gsl_vector_get(x,1));
gsl_matrix_set(J, 0, 0, freesteam_region4_dAdTx(D->A,S));
gsl_matrix_set(J, 0, 1, freesteam_region4_dAdxT(D->A,S));
gsl_matrix_set(J, 1, 0, freesteam_region4_dAdTx(D->B,S));
gsl_matrix_set(J, 1, 1, freesteam_region4_dAdxT(D->B,S));
return GSL_SUCCESS;
#undef D
}
SteamState freesteam_set_pu(double p, double u){
double lb, ub, tol, sol, err;
SolvePUData D = {p, u, 0.};
SteamState S;
int region = freesteam_region_pu(p,u);
switch(region){
case 1:
lb = IAPWS97_TMIN;
ub = REGION1_TMAX;
tol = 1e-9; /* ??? */
zeroin_solve(&pu_region1_fn, &D, lb, ub, tol, &sol, &err);
S = freesteam_region1_set_pT(p,sol);
break;
case 2:
lb = IAPWS97_TMIN;
ub = REGION2_TMAX;
tol = 1e-9; /* ??? */
zeroin_solve(&pu_region2_fn, &D, lb, ub, tol, &sol, &err);
S = freesteam_region2_set_pT(p,sol);
break;
case 4:
lb = 0.;
ub = 1.;
tol = 1e-9; /* ??? */
D.T = freesteam_region4_Tsat_p(p);
//fprintf(stderr,"%s: (%s:%d): p = %g\n",__func__,__FILE__,__LINE__,D.p);
zeroin_solve(&pu_region4_fn, &D, lb, ub, tol, &sol, &err);
S = freesteam_region4_set_Tx(D.T,sol);
break;
case 3:
/* FIXME looks like a problem with the derivative routines here? */
{
int status;
SteamState guess = freesteam_region3_set_rhoT(IAPWS97_RHOCRIT,IAPWS97_TCRIT);
S = freesteam_solver2_region3('p','u', p, u, guess, &status);
if(status){
fprintf(stderr,"%s (%s:%d): Failed solve in region 3 for (p = %g MPa, u = %g kJ/kg\n"
,__func__,__FILE__,__LINE__,p/1e6,u/1e3);
//exit(1);
}
}
break;
default:
fprintf(stderr,"%s (%s:%d): Region '%d' not implemented\n",__func__,__FILE__,__LINE__,region);
exit(1);
}
return S;
}
SteamState freesteam_solver2_region4(FREESTEAM_CHAR A, FREESTEAM_CHAR B, double atarget, double btarget, SteamState guess, int *retstatus){
const gsl_multiroot_fdfsolver_type *T;
gsl_multiroot_fdfsolver *s;
int status;
size_t iter = 0;
const size_t n = 2;
Solver2Data D = {A,B,solver2_region4_propfn(A), solver2_region4_propfn(B), atarget,btarget};
gsl_multiroot_function_fdf f = {®ion4_f, ®ion4_df, ®ion4_fdf, n, &D};
gsl_vector *x = gsl_vector_alloc(n);
assert(guess.region==4);
gsl_vector_set(x, 0, guess.R4.T);
gsl_vector_set(x, 1, guess.R4.x);
T = gsl_multiroot_fdfsolver_gnewton;
s = gsl_multiroot_fdfsolver_alloc(T, n);
gsl_multiroot_fdfsolver_set(s, &f, x);
//region4_print_state(iter, s);
do{
iter++;
status = gsl_multiroot_fdfsolver_iterate(s);
//region4_print_state(iter, s);
if(status){
/* check if solver is stuck */
break;
}
status = gsl_multiroot_test_residual(s->f, 1e-7);
} while(status == GSL_CONTINUE && iter < 20);
fprintf(stderr,"status = %s\n", gsl_strerror (status));
SteamState S = freesteam_region4_set_Tx(gsl_vector_get(s->x,0), gsl_vector_get(s->x,1));
gsl_multiroot_fdfsolver_free(s);
gsl_vector_free(x);
*retstatus = status;
if(status)fprintf(stderr,"%s (%s:%d): %s: ",__func__,__FILE__,__LINE__,gsl_strerror(status));
//freesteam_fprint(stderr,S);
return S;
}
