def activationFunctionASIG(self, x):
        """
        Determine the activation of a node based on that nodes net input.
        """
        def act(v):
            if   v < -15.0: return 0.0
            elif v >  15.0: return 1.0
            else: return 1.0 / (1.0 + Numeric.exp(-v))
        return Numeric.array(list(map(act, x)), 'f')