def randomize(self, alive_fraction):
    a = self.db.get_data('Cell.alive')
    a.fill(False)
    a[(np.random.uniform(size=a.shape) < alive_fraction)] = True
def randomize(self, alive_fraction):
    a = self.db.get_data('Cell.alive')
    a.fill(False)
    a[(np.random.uniform(size=a.shape) < alive_fraction)] = True