负半径对于椭球体意味着什么

Question

我一直在使用来自https://github.com/aleksandrbazhin/ellipsoid_fit_python的Ellipsoid fit python模块，我发现它基本上是比较好的，但我最近通过它运行了一些数据，我注意到我得到了很多负半径：

points = np.array([[ 0.09149729,  0.03684962, -0.02292631],
       [ 0.09248848,  0.03587991, -0.02036695],
       [ 0.09290258,  0.03932948, -0.02168421],
       [ 0.11715488,  0.02191344, -0.03957262],
       [ 0.09938425,  0.02479092, -0.01535327],
       [ 0.09911977,  0.02794963, -0.01118133],
       [ 0.12063151,  0.03880141, -0.01510232],
       [ 0.11984777,  0.02508288, -0.02870339],
       [ 0.10012223,  0.02373475, -0.02195443],
       [ 0.09790555,  0.02624265, -0.01190708],
       [ 0.10180188,  0.02583424, -0.01340349],
       [ 0.12224249,  0.02299428, -0.03712141],
       [ 0.12637239,  0.03043518, -0.02760782],
       [ 0.12438858,  0.02703345, -0.02828939],
       [ 0.0974825 ,  0.02577809, -0.01916746],
       [ 0.12031736,  0.02822308, -0.03366493],
       [ 0.1021885 ,  0.02674174, -0.03242179],
       [ 0.10101997,  0.03994928, -0.01519449],
       [ 0.12693756,  0.03200349, -0.02941957],
       [ 0.09250743,  0.0386544 , -0.02030381],
       [ 0.11748721,  0.02688126, -0.02310617],
       [ 0.11888266,  0.03919276, -0.01614771],
       [ 0.1175726 ,  0.02390139, -0.03775631],
       [ 0.09802308,  0.02690862, -0.02278864],
       [ 0.0974572 ,  0.02665273, -0.0109419 ],
       [ 0.11867452,  0.03764389, -0.01400771],
       [ 0.10302589,  0.04016999, -0.01659405],
       [ 0.12613943,  0.03701292, -0.02291183],
       [ 0.12622967,  0.03926508, -0.01887258]])

centre3, radii3, evecs3, v3 = ellipsoid_fit(points )
radii3 = [-0.00490022,  0.05778404, -0.01372089]

出于某种原因，ellipsoid_fit函数将符号应用于半径-我不明白为什么半径会有符号，而不仅仅是绝对值

我可以忽略这些符号，取绝对值吗？如果不是，负半径意味着什么