code: def calc_vq_v1(self):
      
      der = self.parameters.derived.fastaccess
      flu = self.sequences.fluxes.fastaccess
      aid = self.sequences.aides.fastaccess
      aid.vq = 2.*aid.v+der.seconds/der.nmbsubsteps*flu.qz
docs: Calculate the auxiliary term.
  
      Required derived parameters:
        |Seconds|
        |NmbSubsteps|
  
      Required flux sequence:
        |QZ|
  
      Required aide sequence:
        |llake_aides.V|
  
      Calculated aide sequence:
        |llake_aides.VQ|
  
      Basic equation:
        :math:`VQ = 2 \\cdot V + \\frac{Seconds}{NmbSubsteps} \\cdot QZ`
  
      Example:
  
          The following example shows that the auxiliary term `vq` does not
          depend on the (outer) simulation step size but on the (inner)
          calculation step size defined by parameter `maxdt`:
  
          >>> from hydpy.models.llake import *
          >>> parameterstep('1d')
          >>> simulationstep('12h')
          >>> maxdt('6h')
          >>> derived.seconds.update()
          >>> derived.nmbsubsteps.update()
          >>> fluxes.qz = 2.
          >>> aides.v = 1e5
          >>> model.calc_vq_v1()
          >>> aides.vq
          vq(243200.0)