Why cerebro.broker.getvalue() is nan

atori

Hi. I'm Japanese boy.
I am trying a simple moving average strategy to grasp the behavior of backtrader.
However, at the end of the test getvalue becomes nan.
What's wrong?

・bt_data
datetime stock_name high low close
2018-08-14 S&P500 2843.1101 2826.5801 2839.9600
2018-08-15 S&P500 2827.9500 2802.4900 2818.3701
2018-08-16 S&P500 2850.4900 2831.4399 2840.6899
2018-08-17 S&P500 2855.6299 2833.7300 2850.1299
2018-08-20 S&P500 2859.7600 2850.6201 2857.0500

#Strategy
class Stg_MovingAgerage(bt.Strategy):

    params = (
        ('maperiod', 15), 
    )
    
    def __init__(self):

        self.dataclose = self.datas[0].close 
        self.order = None
        self.buyprice = None
        self.buycomm = None
    
        self.sma = bt.indicators.SimpleMovingAverage(self.datas[0], period=self.params.maperiod)
    
    
    def notify_order(self, order):
        if order.status in [order.Submitted, order.Accepted]:
            return

        if order.status in [order.Completed]:
            self.bar_executed = len(self)

        elif order.status in [order.Canceled, order.Margin, order.Rejected]:
            print('Order Canceled/Margin/Rejected')

        self.order = None
    

    def notify_trade(self, trade):
        """トレード収支"""
        if not trade.isclosed:
            return

        print(str(self.datas[0].datetime.date(0)) + ' OPERATION PROFIT, GROSS %.2f, NET %.2f' % (trade.pnl, trade.pnlcomm))

    
    
    def next(self):
        """トレード実行"""

        #print(str(self.datas[0].datetime.date(0)) + ' Close, %.2f' % self.dataclose[0] +  '  SMA, %.2f' % self.sma[0] )
        
        if self.order:
            return

        if not self.position:
            if self.dataclose[0] > self.sma[0]:
                self.order = self.buy()

        else:
            if self.dataclose[0] < self.sma[0]:
                self.order = self.sell()
    
    def stop(self):
        print('-------------------------')
        print('★RESULT★ Ending Value %.2f' %(self.broker.getvalue()))

cerebro = bt.Cerebro()
bt_data = bt.feeds.PandasData(dataname=df_input,datetime='datetime',close='close',openinterest=None)
cerebro.adddata(bt_data)

cerebro.broker.setcash(100000.0)
cerebro.broker.setcommission(commission=0.001)
cerebro.broker.getvalue()

# Add a strategy
cerebro.addstrategy(Stg_MovingAgerage)

cerebro.run()

cerebro.broker.getvalue()

★RESULT★ Ending Value nan

backtrader

You don't have opening prices, which makes all opening prices default to NaN, hence the resulting NaN

atori

@backtrader

Thank you for your reply.

I corrected it and succeeded.

bt_data = bt.feeds.PandasData(dataname=df_input,datetime='datetime',open='open',high='high',low='low',close='close',volume=None,openinterest=None)

If the data source does not provide an indicator of open or high, only close,What should I do?
Even if you did the following, it failed.

bt_data = bt.feeds.PandasData(dataname=df_input,datetime='datetime',open=None,high=None,low=None,close='close',volume=None,openinterest=None)

backtrader

@atori said in Why cerebro.broker.getvalue() is nan:

What should I do?

Use some of the other prices to fill in the missing prices. But the broker needs OHLC to fulfill its tasks. If you don't use the broker, because you are only testing, for example, an indicator, you can use only the components you need.

MoorsTech

I've done something similar once when I used backtrader to simulate betting.
In your case you could try this:

bt_data = bt.feeds.PandasData(dataname=df_input,datetime='datetime', open='close', high='close', low='close',close='close', volume=None, openinterest=None)

However you should know that this ought to basically limit you to market orders, I wouldn't recommend using more complex order types with this as they'll likely behave in ways that are unique to your simulation ;)
If you want to run "serious" simulations with backtrader, you really need to get yourself some OHCL data.

Cheers

atori

Thank you for your reply.
I'll give it a try.And I will use OHCL data as much as possible.
I am sorry for weird English.

backtrader

@atori said in Why cerebro.broker.getvalue() is nan:

I am sorry for weird English.

No need to apologize. I am sure everyone's Japanese is much worse than your English. Just keep on practicing (practice makes perfection ... or at least allows you to become better even if not perfect)