--- /dev/null
+function rho = spectral_radius(A)
+ %
+ % Compute the spectral radius of ``A``, which is not necessarily
+ % Hermitian.
+ %
+ % This is slow. Don't use it on big matrices.
+ %
+ % INPUT:
+ %
+ % ``A`` -- The matrix whose spectral radius you want.
+ %
+ % OUTPUT:
+ %
+ % ``rho`` -- The spectral radius of ``A``.
+ %
+ rho = max(abs(eig(A)));
+end