帮我写一个c++的三维坐标系

好的，以下是一个简单的 C++ 三维坐标系实现：

#include <iostream>
using namespace std;

struct Point3D {
    double x, y, z;
};

class CoordinateSystem {
private:
    Point3D origin;     // 坐标系原点
public:
    CoordinateSystem() {
        origin.x = origin.y = origin.z = 0.0;
    }

    void setOrigin(double x, double y, double z) {
        origin.x = x;
        origin.y = y;
        origin.z = z;
    }

    void drawPoint(Point3D p) {
        cout << "(" << p.x << ", " << p.y << ", " << p.z << ")" << endl;
    }

    void drawAxis() {
        cout << "x-axis: ";
        drawPoint(origin);
        drawPoint({ origin.x + 1.0, origin.y, origin.z });

        cout << "y-axis: ";
        drawPoint(origin);
        drawPoint({ origin.x, origin.y + 1.0, origin.z });

        cout << "z-axis: ";
        drawPoint(origin);
        drawPoint({ origin.x, origin.y, origin.z + 1.0 });
    }
};

int main() {
    CoordinateSystem cs;
    cs.setOrigin(1.0, 2.0, 3.0);
    cs.drawAxis();
    return 0;
}

这个程序定义了一个三维坐标系类 `CoordinateSystem`，包含一个坐标系原点 `origin` 和三个方法：`setOrigin` 设置坐标系原点，`drawPoint` 绘制一个三维点，`drawAxis` 绘制三个坐标轴。在 `main` 函数中，我们创建了一个坐标系对象 `cs`，设置坐标系原点为 `(1.0, 2.0, 3.0)`，并绘制坐标轴。