code: def killCells(self, killCellPercent):
      
      if killCellPercent <= 0:
        return
  
      numHiddenNeurons = self.net.numHiddenNeurons
  
      numDead = round(killCellPercent * numHiddenNeurons)
      zombiePermutation = numpy.random.permutation(numHiddenNeurons)
      deadCells = zombiePermutation[0:numDead]
      liveCells = zombiePermutation[numDead:]
  
      self.net.inputWeights = self.net.inputWeights[liveCells, :]
      self.net.bias = self.net.bias[:, liveCells]
      self.net.beta = self.net.beta[liveCells, :]
      self.net.M = self.net.M[liveCells, liveCells]
      self.net.numHiddenNeurons = numHiddenNeurons - numDead
docs: kill a fraction of cells from the network