不规则多边形的面积计算

1、C++ 方法

template <class T>
T  Convex_Hull_Volume(std::vector<T>  &x, std::vector<T>  &y)
{
    if(x.size() != y.size()){
        std::cout<<"Err: num mismatch:"<<x.size()<<" != "<<y.size()<<std::endl;
        return 0.0;
    }
    std::vector<T>   xp(x.size()+1);
    std::vector<T>   yp(y.size()+1);
    xp.assign(x.begin(), x.end());
    yp.assign(y.begin(), y.end());
    xp.push_back(xp[0]);
    yp.push_back(yp[0]);
    T  sumx = 0.0, sumy = 0.0;
    for(int k=0; k<x.size(); k++){
        sumx += xp[k]*yp[k+1];
        sumy += xp[k+1]*yp[k];
    }
    return (std::abs(sumx-sumy)/2.0);
}

2、Python方法

先安装包: pip3 install polygon-math

from polygon_math import polygon
Vertices = [[x0,y0],[x1,y1],[x2,y2],...]   # 2D-coordinates of vertices
pg = polygon(Vertices)
pg.Area    #多边形面积