#include <cmath>
#include "iterativo.h"

double x=0, y=0, z=0;
double mu0=4.*M_PI*1.E-7;

double radius=0.155;   // 15.5 cm
double distanza=0.155; // 15.5 cm
double current=1.;     // 1 A

void setPoint(double xset, double yset, double zset) {
  x=xset;
  y=yset;
  z=zset;
}

double intBx(double theta) {
  double rx = x-radius*cos(theta);
  double ry = y-radius*sin(theta);
  double r  = sqrt(rx*rx+ry*ry+z*z);
  return z*cos(theta)/pow(r,3);
}

double intBy(double theta) {
  double rx = x-radius*cos(theta);
  double ry = y-radius*sin(theta);
  double r  = sqrt(rx*rx+ry*ry+z*z);
  return z*cos(theta)/pow(r,3);
}

double intBz(double theta) {
  double rx = x-radius*cos(theta);
  double ry = y-radius*sin(theta);
  double r  = sqrt(rx*rx+ry*ry+z*z);
  return (radius-y*sin(theta)-x*cos(theta))/pow(r,3);
}

double Bx(double xset, double yset, double zset) {
  setPoint(xset,yset,zset);
  return mu0*current* /* integrale di intBx */ /(4*M_PI);
}

double By(double xset, double yset, double zset) {
  setPoint(xset,yset,zset);
  return mu0*current* /* integrale di intBy */ /(4*M_PI);
}

double Bz(double xset, double yset, double zset) {
  setPoint(xset,yset,zset);
  return mu0*current* /* integrale di intBz */ /(4*M_PI);
}