code: def activationFunctionASIG(self, x):
          
          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')
docs: Determine the activation of a node based on that nodes net input.