def center_eigenvalue_diff(mat):
N = len(mat)<EOL>evals = np.sort(la.eigvals(mat))<EOL>diff = np.abs(evals[N/<NUM_LIT:2>] - evals[N/<NUM_LIT:2>-<NUM_LIT:1>])<EOL>return diff<EOL>
Compute the eigvals of mat and then find the center eigval difference.