ppoint2.cpp

it is a usefull thing

//=====================================
// PPoint2.cpp
// 极坐标版本
//=====================================
#include"ppoint.h"
#include<cmath>
using namespace std;
//-------------------------------------
void PPoint::set(double ix,double iy){
  x=atan2(iy, ix);
  y=sqrt(ix*ix+iy*iy);
}//------------------------------------
double PPoint::xOffset(){
  return y*cos(x);
}//------------------------------------
double PPoint::yOffset(){
  return y*sin(x);
}//------------------------------------
double PPoint::angle(){
  return (180/3.14159)*x;
}//------------------------------------
double PPoint::radius(){
  return y;
}//------------------------------------