delaunay2D.py 文件源码

def circumcenter(self, tri):
        """Compute circumcenter and circumradius of a triangle in 2D.
        Uses an extension of the method described here:
        http://www.ics.uci.edu/~eppstein/junkyard/circumcenter.html
        """
        pts = np.asarray([self.coords[v] for v in tri])
        pts2 = np.dot(pts, pts.T)
        A = np.bmat([[2 * pts2, [[1],
                                 [1],
                                 [1]]],
                      [[[1, 1, 1, 0]]]])

        b = np.hstack((np.sum(pts * pts, axis=1), [1]))
        x = np.linalg.solve(A, b)
        bary_coords = x[:-1]
        center = np.dot(bary_coords, pts)

        # radius = np.linalg.norm(pts[0] - center) # euclidean distance
        radius = np.sum(np.square(pts[0] - center))  # squared distance
        return (center, radius)