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## Re: Issues with eigs

 From: Thomas D. Dean Subject: Re: Issues with eigs Date: Sat, 8 Sep 2018 12:13:13 -0700 User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1

There is a problem here. I know about roundoff error, etc. Even with roundoff error, I believe I should get the same result every time I run this.
```
octave:722> eigs(m1,m0)
ans =

0.00026 - 2672325.75636i
0.00026 + 2672325.75636i
0.00000 + 2639890.67488i
0.00000 - 2639890.67488i
-0.00007 - 2587678.50828i
-0.00007 + 2587678.50828i

octave:723> eigs(m1,m0)
ans =

0.00050 - 2672274.01721i
0.00050 + 2672274.01721i
-0.00058 + 2639991.91956i
-0.00058 - 2639991.91956i
-0.00005 - 2587660.78340i
-0.00005 + 2587660.78340i

octave:724> eigs(m1,m0)
ans =

0.00014 + 2672332.27197i
0.00014 - 2672332.27197i
-0.00030 - 2639921.38497i
-0.00030 + 2639921.38497i
0.00001 - 2587707.77163i
0.00001 + 2587707.77163i

```
With Scipy, I get the same result every time I run it. I verified that both octave and numpy read the matrix the same way - non-zero values are the same and in the same location.
```
#!/usr/bin/python3

import numpy as np
from scipy import linalg as la

e1, w1 = la.eig(m0, m1)
e2, w2 = la.eig(m0, m1)
for idx in range(len(e1)):
if e1[idx] != e2[idx]:
print(e1[idx], ' != ', e2[idx])

Tom Dean

```