坐标

#ifndef HEADER_PPOINT//头文件卫士
 #define HEADER_PPOINT
 class PPoint
 {
     double x,y;//直角坐标或极坐标
 public:
     PPoint(double ix,double iy);//设置坐标
     double xOffset();//设置轴分量x
     double yOffset();//设置y轴分量
     double angle();//极坐标弧角
     double radius();//极坐标半径
 };
 #endif//HEADER_PPOINT
 //---------------------------------------
 #include"ppoint.h"
 #include<iostream>
 using namespace std;
 int main()
 {
     for(double x,y;cout<<"Enter x and y:\n"&&cin>>x>>y&&x>=0;)//
     {
         PPoint p(x,y);
         cout<<"angle="<<p.angle()<<",radius="<<p.radius()<<",xOffset="<<p.xOffset()<<",yOffset"<<p.yOffset()<<"\n";
     }
 }
 //-------------------------------
 #include"ppoint.h"
 #include<cmath>
 using namespace std;
 PPoint::PPoint(double ix,double iy)
 {
     x=ix,y=iy;
 }
 double PPoint::xOffset()
 {
     return x;
 }
 double PPoint::yOffset()
 {
     return y;
 }
 double PPoint::angle()
 {
     return (180/3.14159)*atan2(y,x);//atan2得到的是弧度
 }
 double PPoint::radius()
 {
     return sqrt(x*x+y*y);
 }