output function

def create_function_f_y(self):
        """output function"""
        return ca.Function(
            'y',
            [self.t, self.x, self.m, self.p, self.c, self.ng, self.nu],
            [self.y_rhs],
            ['t', 'x', 'm', 'p', 'c', 'ng', 'nu'], ['y'], self.func_opt)