这个程序的输出如下：
U:
[[0.408417010949, -0.864440453267, 0.293152260647], [-0.305207244576, 0.173347705798, 0.936375518023], [-0.860258149061, -0.471903883910, -0.193035336985]]
sigma:
[[18.656434256571, 0.000000000000, 0.000000000000], [0.000000000000, 7.854856616370, 0.000000000000], [0.000000000000, 0.000000000000, -5.911683464935]]
V:
[[-0.785962148615, 0.111210582619, -0.608190518882], [0.269056841400, -0.824140029385, -0.498399065068], [-0.556661402506, -0.555360620028, 0.617820900166]]
为什么svd分解的奇异值会有负数-5.911683464935？应该都是非负数啊。如何解决呢？谢谢