- #1

nenyan

- 67

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- TL;DR Summary
- different methods give different results. They are not consistent.

**Summary:**different methods give different results. They are not consistent.

**Summary:**different methods give different results. They are not consistent.

I use two different methods to detect whether a matrix is singular. The result of calculating the determinant of a 9-order square matrix is far greater than zero. The result of calculating the rank of the same square matrix is 8. Why are the results inconsistent?

singularity:

```
import numpy as np
from numpy.linalg import inv
a = np.loadtxt('data/d0.txt')
print(a.shape)
print(np.linalg.det(a))
print(np.linalg.matrix_rank(a))
```

*(9, 9)*

2.3274769078093922e+52

8

2.3274769078093922e+52

8

the attached is one of those matrixes. There are hundreds of them.

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