@backtrader said in Problem with custom ohlc vars:

@arrr said in Problem with custom ohlc vars:

However if I call same self.make_ohlc() from self.next() - it works

I fail to understand what the problem is. You have for sure a very clear idea about what troubles you, but you have already said it works. What you want to do with the data is of course unknown.

Sorry for confusing explanation. It technically works, but I did not check if it returns correct data and, as for me, the code looks pretty weird :)

@backtrader said in Problem with custom ohlc vars:

@arrr said in Problem with custom ohlc vars:

this gonna work fine, considering I'm using data replay?

What should work fine? The info you have provided in this thread is close to none. You simply say that you cannot get data in __init__, which is something obvious.

I mean calling self.make_ohlc() on every next() and operating what it returns as ohlc data

@backtrader this gonna work fine, considering I'm using data replay?

I'm trying to maintain code compatibility with my production environment, where I'm storing ohlc data in a dict:
self.ohlc = {-3: {'o': 153.252, 'h': 155.84, 'l': 149.49, 'c': 152.42, 'vol': 155395.333}, -2: {'o': 152.417, 'h': 162.4, 'l': 149.78, 'c': 155.65, 'vol': 255543.915}, -1: {'o': 155.7, 'h': 161.04, 'l': 150.88, 'c': 158.48, 'vol': 297664.05400000006}, 0: {'o': 158.71, 'h': 167.0, 'l': 158.51, 'c': 162.0, 'vol': 189163.71099999998}}
where self.ohlc[0]['l] is the low if the current bar and self.ohlc[-3]['h'] stands for high 3 bars ago.
I was trying to replicate the same with backtrader by doing:

    def make_ohlc(self):
        ohlc_dict = {}
        for x in range(-3, 1):
            ohlc = {'o': self.datas[0].open[x], 'h': self.datas[0].high[x], 'l': self.datas[0].low[x], 'c': self.datas[0].close[x]}
            ohlc_dict[x] = ohlc
        return ohlc_dict

and calling it from init:
self.ohlc = self.make_ohlc()
But once I do that - I'm getting weird error:

  File "/Users/arrrr/PycharmProjects/backtrader/reverse.py", line 217, in <module>
    cerebro.run()
  File "/Users/arrrr/PycharmProjects/backtrader/venv/lib/python3.6/site-packages/backtrader/cerebro.py", line 1127, in run
    runstrat = self.runstrategies(iterstrat)
  File "/Users/arrrr/PycharmProjects/backtrader/venv/lib/python3.6/site-packages/backtrader/cerebro.py", line 1217, in runstrategies
    strat = stratcls(*sargs, **skwargs)
  File "/Users/arrrr/PycharmProjects/backtrader/venv/lib/python3.6/site-packages/backtrader/metabase.py", line 88, in __call__
    _obj, args, kwargs = cls.doinit(_obj, *args, **kwargs)
  File "/Users/arrrr/PycharmProjects/backtrader/venv/lib/python3.6/site-packages/backtrader/metabase.py", line 78, in doinit
    _obj.__init__(*args, **kwargs)
  File "/Users/arrrr/PycharmProjects/backtrader/reverse.py", line 50, in __init__
    self.make_ohlc()
  File "/Users/arrrr/PycharmProjects/backtrader/reverse.py", line 55, in make_ohlc
    ohlc = {'o': self.dataopen[x], 'h': self.datahigh[x], 'l': self.datalow[x],
  File "/Users/arrrr/PycharmProjects/backtrader/venv/lib/python3.6/site-packages/backtrader/linebuffer.py", line 163, in __getitem__
    return self.array[self.idx + ago]
IndexError: array index out of range

However if I call same self.make_ohlc() from self.next() - it works (it's obvious that calling it every bar is not a proper way to handle this)
Any ideas what I'm doing wrong?

@backtrader When using 2 data feeds backtrader will call next() on every bar in each feed. Since bt takes bars from both feeds, sorts them from oldest to newest and then runs in a single flow, feeds become "mixed". My problem is that I don't know which bar from which feed is currently calling next() and therefore I can't call indicator functions on daily feed and skip them on minute one. So my question is how do I know which feed a certain bar comes from?

@backtrader I mean, that if you run it with 2 data feeds, but without looping them. So it will basically mix data from both sources in a single output. Long story short: is there any way to determine which feed a bar comes from?

I've googled about using multiple datafeeds with backtrader and it seems, that all available examples (including the docs) are looping thru the datasets, however I would like to use them simultaneously, is that possible?

Btw is it possible to use 2 sets of data: daily bars for indicators and smaller (hourly, 15 min or whatever) to place and process orders? In this case updating order (cancel + placing the new one) will take 2 small bars instead of skipping a full day.

I see. Any time estimates on v2?

Hi
I've got a strategy, where I need to update my order (or cancel and immediately place a new one) almost every period, however it seems to be impossible with backtrader right now. The only thing I can do is: cancel my order => wait for the next() run => place a new order, which means I've got a period without any live orders.
Is there any way to handle this properly?