对对称矩阵的对称性测试失败

Question

我在内存中有一个对称矩阵(4x4)。不幸的是，sum( originalMatrix != t( originalMatrix ))= 6，所以我把这个矩阵输入并读回内存。现在sum( dputMatrix!= t( dputMatrix) )= 0。这是怎么可能的，我如何测试我的内存矩阵的对称性？

originalMatrix = ...
sum( originalMatrix != t( originalMatrix ) )  # results in 6
dput( originalMatrix )
dputMatrix = structure(c(0.00117771346463494, -1.57864028664711e-05, 0.000293652924987303, 
-9.85387333663002e-05, -1.57864028664711e-05, 0.000194782042576016, 
6.9133672862693e-05, 4.23792732612071e-05, 0.000293652924987303, 
6.9133672862693e-05, 0.00046216043028767, 2.70172523991749e-05, 
-9.85387333663002e-05, 4.23792732612071e-05, 2.70172523991749e-05, 
0.00017694896679169), .Dim = c(4L, 4L), .Dimnames = list(c("a00088630", 
"a0091n", "a01010", "a01307810"), c("a00088630", "a0091n", "a01010", 
"a01307810")))
sum( dputMatrix != t( dputMatrix ) )  # results in 0!!!

Answer 1

这是FAQ 7.31的一种表现。请注意，如果要将R对象保存为全精度，则应使用save()。

请打钩！