如何组织或排序std :: vector< cv :: Point2f> [英] how to organize or sort a std::vector <cv::Point2f>

问题描述

我有一个充满cv :: Point的向量，并且我想组织这个向量，以便具有最小x和y值的Point应该是第一个，最后一个应该具有最高的x，y值?任何想法我该怎么做?

I have a vector full of cv::Point and I want to organize this vector so, that the Point with the smallest x and y value should be the first and the last one should have the highst x,y value ? any Idea how can I do that ?

推荐答案

使用 std :: sort .

std::sort(vec.begin(), vec.end(), [](const cv::Point2f &a, const cv::Point2f &b) {
    return (/* This is where you would compare a and b however you want */);
});

真的，很难说出您认为最大(x，y)对和最小(x，y)对的含义.一种解决方案是添加坐标以赋予其大小.

Really, it's quite hard to tell what you deem as the greatest (x,y) pair and the least (x,y) pair. One solution is to add the coordinates to give them a magnitude.

我将使用距原点的距离:返回a.x * a.x + a.y * a.y<b.x * b.x + b.y * b.y

I'd use the distance from the origin: return a.x*a.x + a.y*a.y < b.x*b.x + b.y*b.y

如果您无法使用C ++ 11功能，则等同于上述解决方案:

In case you can't use C++11 functionality, here's the equivalent of the above solution:

bool point_comparator(const cv::Point2f &a, const cv::Point2f &b) {
    return (/* Your expression */);
}

std::sort(vec.begin(), vec.end(), point_comparator);

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