Negative Eigenvalues found in 12x12 Matrix

I have attached a 12x12 matrix that I need to find the eigenvalues for. I have tried the following Eigenvalue function, (MATLAB Version: 9.5.0.944444 (R2018b))

[Mod1, Eigs1] = eig(cor)

I wanted to ask why I am getting negative eigenvalues in the matrix. My knowledge of matrices isnt the best, so is it due to the type of matrix "cor" is or is it something to do with the function eigs limitations? From theory I know the eigenvalues should be positive for what I am trying to do, so if theres something wrong with the matrix I can look at it and work backwards to fix the problem.

Any help would be highly appreciated.

Answer 1

[Jon]

I would trust the result of the eig function. If you do not think your matrix, cor, should have negative eigenvalues, then you must have made some mistake earlier in computing your matrix cor.

You could post the relevant part of your code here so others can see and maybe help. Please use the code button on the MATLAB Answers toolbar to have it nicely formatted