Checks if the solution has converged to within the specified
        tolerance.

def _check_convergence(self, P, Q, i, type):
        """ Checks if the solution has converged to within the specified
        tolerance.
        """
        normP = linalg.norm(P, Inf)
        normQ = linalg.norm(Q, Inf)

        if self.verbose:
            logger.info("  %s  %3d   %10.3e   %10.3e" % (type,i, normP, normQ))

        if (normP < self.tolerance) and (normQ < self.tolerance):
            converged = True
        else:
            converged = False

        return converged