def _compile_fdpf(self):
        """Fast Decoupled Power Flow execution: Implement g(y)
        """
        string = '"""\n'
        string += 'system.dae.init_g()\n'
        for pflow, gcall, call in zip(self.pflow, self.gcall, self.gcalls):
            if pflow and gcall:
                string += call
        string += 'system.dae.reset_small_g()\n'
        string += '\n'
        string += '"""'
        self.fdpf = compile(eval(string), '', 'exec')