#include <iostream>
int main()
{
	float y1 = -0.000000;
	float x1= -0.000000;
	float y2 = 0.000000;
	float x2 = -0.000000;
	float deg1 = atan2(y1, x1);
	float deg2 = atan2(y2, x2);
	printf("deg1: %f and deg2: %f\n", deg1, deg2);
	getchar();
	return 0;
}
当x值为0,y值为-0.000000/0.000000时候,返回值需要注意
deg1: -3.141593 and deg2: 3.141593
原文:https://www.cnblogs.com/flyinggod/p/13433858.html