def calculate(self, transaction):
        if transaction.amount == 0:
            return 0.0, 0.0

        return abs(self.cost / transaction.amount), self.cost
Override the call to be able to scale automatically the axis.
dataset/ETHPy150Open quantopian/zipline/zipline/finance/commission.py/PerTrade.calculate--crossover with--dataset/ETHPy150Open enthought/mayavi/mayavi/tools/helper_functions.py/BarChart.__call_internal__