int runge(double EPS, const char*filename)
{
struct vect v; // основной вектор координат
struct vect k[DIM]; // числа Рунгe
//*инициализация чисел Рунге */
for (int i=0;i<DIM;i++)
init(k + i,RK_NUM);
/* Вектор функций и расчётные коэффициенты */
double (*f[DIM]) (struct vect v, double t);
struct vect a, p, pp;
struct vect b[RK_NUM];
/* инициализация вектора функций и коэффициентов */
Create_Vect_func(f); //
RK_koeff(b,&a,&p,&pp);
double h = H_0; // шаг
double t = 0; // время
double errflag = 0;
FILE *file = fopen(filename, "w");
if (file == NULL) errflag = -1;
else{
fprintf(file, "t \t x \t y\n");
/* вводим начальные условия */
initials(&v);
printf("%d\n",a.length);
print(v);
//runge_step(&h,v,t, f, b, a, k);// вводим начальные значения чисел Рунге
//h = new_h(EPS,h,k,v); // обновляем шаг
//new_k(h,k,x,y,u,v); // ежели он изменился -- обновим числа Рунге
for (t = 0;t<=WORK_TIME+h;t+=h){
// если мы в нужной точке T, 3T/4, T/2, T/4, то flag == 1
/* обновим координаты */
/*
fprintf(file, "%e", t);
fprint(v,file);
fprintf(file, "\n");
*/
h = new_step( EPS, h, t, v, k, a, b, p, pp, f);
/* обновляем числа Рунге */
// printf("(!)\n" );
fprintf(file, "%e", t);
fprint(v,file);
fprintf(file, "\n");
runge_step(h,v,t, f, b, a, k);
new_parametrs(h,t,&v,k,p);
if (h<H_DEFAULT) {errflag = -3; break;} // на случай особых точек
}
}
printf("final step = %e;\n", h);
fclose(file);
return errflag;
}
static void
sH(void *userData, const char *name, const char **atts)
{
charData_discard();
if (!strcmp(name,"system"))
{
const char *det;
const char *mev;
char *endll;
mev = findAttr(atts,"mev");
curr_system = new_system();
curr_system->n = (const char *)npool_copy((unsigned char *)findAttr(atts,"n"),context->cpool);
curr_system->mev = new_count();
curr_system->mev->num = strtoll(mev,&endll,10);
curr_system->mev->den = (int)strtol(endll+1,&endll,10);
curr_system->meu = (char *)npool_copy((unsigned char *)endll,
context->cpool);
hash_add(context->systems,
(const unsigned char *)curr_system->n,curr_system);
if ((det = findAttr(atts,"det")))
hash_add(context->sysdets,
npool_copy((unsigned char*)det,context->cpool),
curr_system);
}
else if (!strcmp(name,"step"))
{
struct nsa_step *curr_step = new_step();
const char *overt = findAttr(atts,"overt");
const char *aev = findAttr(atts,"aev");
const char *sex = findAttr(atts,"sex");
char *slash;
int overt_star;
curr_step->ecf = (const char *)npool_copy((unsigned char *)findAttr(atts,"ecf"),context->cpool);
curr_step->etr = (const char *)npool_copy((unsigned char *)findAttr(atts,"etr"),context->cpool);
curr_step->atf = (const char *)npool_copy((unsigned char *)findAttr(atts,"atf"),context->cpool);
curr_step->utf = (const char *)npool_copy((unsigned char *)findAttr(atts,"utf"),context->cpool);
if (sex && *sex == 'a') /* horrible cheat! */
curr_step->sex = nsa_sex_asz_axis;
curr_step->sys = curr_system;
list_add(curr_system->steps,curr_step);
if (aev && *aev)
{
curr_step->aev = new_count();
slash = strchr(aev,'/');
if (!slash)
{
fprintf(stderr,"nsa: system %s/step %s: bad AEV (should be n/1; actual='%s')\n",curr_system->n,curr_step->atf,aev);
curr_step->aev->num = 0;
curr_step->aev->den = 1;
}
else
{
curr_step->aev->num = strtoll(aev,NULL,10);
curr_step->aev->den = (int)strtol(slash+1,NULL,10);
}
}
curr_step->node = curr_system->steps->last;
curr_step->sys = curr_system;
if (!overt || !*overt || strcmp(overt,"no"))
overt_star = 0;
else
overt_star = 1;
/* sH_index_step(curr_step->ecf, curr_step); */
/* sH_index_step(curr_step->etr, curr_step); */
sH_index_step(curr_step->utf, curr_step, overt_star);
if (curr_step->atf && strcmp(curr_step->utf,curr_step->atf))
sH_index_step(curr_step->atf, curr_step, overt_star);
}
else if (!strcmp(name,"ok-com-heads"))
{
curr_comhead_sys = (const char *)npool_copy((unsigned char *)findAttr(atts,"sys"),context->cpool);
}
else if (!strcmp(name,"igi"))
last_u = (char *)npool_copy((unsigned char *)findAttr(atts,"u"),context->cpool);
}