# Error in computation of eigenvalues in Sage

Dear all,

I am trying to compute the eigenvalues of the following matrix

```
J = matrix
([[-Q1,0,0,0,omega,0,0,0,0,-A1],[0,-Q2,0,0,0,omega,0,0,0,A1],[0,gamma,Q3,0,0,0,omega,0,0,0],[0,0,sigma,-Q1,0,0,0,omega,0,0],[A2,0,0,0,-Q4,0,0,0,0,0],[0,A2,0,0,0,-Q4,0,0,0,0],[0,0,A2,0,0,0,-Q4,0,0,0],[0,0,0,A2,0,0,0,-Q4,0,0],[0,0,-A3,0,0,0,0,0,-mu_v,0],[0,0,A3,0,0,0,0,0,0,-mu_v]])
J
J.eigenvalues()
```

Unfortunately am getting the following error.

```
*#0:
eigenvalues(mat=matrix([-_SAGE_VAR_Q1,0,0,0,_SAGE_VAR_omega,0,0,0,0,-_SA\
GE_VAR_A1],[0,-_SAGE_VAR_Q2,0,0,0,_SAGE_VAR_...)
Traceback (click to the left of this block for traceback)
...
TypeError: ECL says: Error executing code in Maxima: part: fell off the
end.*
```

When I try with numerical values however, I get eigenvalues. My problem involves a matrix with characters and I want to know the nature of the eigenvalues so that I may draw certain conclusions. What should I do in order to compute my eigenvalues without an error. Thank you for support.

What are

`Q1`

,`omega`

,`A1`

, etc...? If you do not give full information about your code we can surely not help you.Q1 to Q4, omega,sigma,A1 to A3 and mu_v are characters in the matrix and the rest of the columns are zeros. and they are declared as follows

var('sigma,omega,Q1,Q2,Q3,Q4,A1,A2,A3,mu_v')

you forgot gamma ;-)

Am sorry..omega is in the variable,,,,I forgot. I am sorry for the typo error.