code: def update(self):
          
          damp = self.subpars.pars.control.damp
          self(numpy.clip(damp/(1.+damp), 0., .5))
docs: Update |C1| based on :math:`c_1 = \\frac{Damp}{1+Damp}`.
  
          Examples:
  
              The first examples show the calculated value of |C1| for
              the lowest possible value of |Lag|, the lowest possible value,
              and an intermediate value:
  
              >>> from hydpy.models.hstream import *
              >>> parameterstep('1d')
              >>> damp(0.0)
              >>> derived.c1.update()
              >>> derived.c1
              c1(0.0)
              >>> damp(1.0)
              >>> derived.c1.update()
              >>> derived.c1
              c1(0.5)
              >>> damp(0.25)
              >>> derived.c1.update()
              >>> derived.c1
              c1(0.2)
  
              For to low and to high values of |Lag|, clipping is performed:
              >>> damp.value = -0.1
              >>> derived.c1.update()
              >>> derived.c1
              c1(0.0)
              >>> damp.value = 1.1
              >>> derived.c1.update()
              >>> derived.c1
              c1(0.5)