How to assign arrays to lines?

James Barber

So I'm new to the platform, but I have a question with no answer I can find in the docs.

I have an indicator function I wrote for use outside of backtrader for my own libraries, but I would like to use it for backtesting on backtrader without having to rewrite it specifically for backtrader. So I am wrapping it. When called, it returns a data structure containing a number of arrays. All of these arrays correspond to custom 'Lines'. When trying to assign the arrays to the indicator lines, all values read 'nan' accessing them within a strategy.

So the question is boiled down to why does the following not work? How do I get my oracle'd arrays into custom indicator lines?

{code}
class CustomIndicator(bt.Indicator):
lines = ("custom_line", )

# Price flip is 6 bars
params = (('period', 6),)

def __init__(self):
    self.addminperiod(self.params.period)
    self.line.custom_line =[0.0] * self.data.close.buflen() # => filled with 'nan's when accessed in a strategy

{code}

Is there any way to convert an array to a Line object or mass assign its values into a line?

Would very much appreciate any pointers here

James Barber

clearner code

class CustomIndicator(bt.Indicator):
lines = ("custom_line", )

# Price flip is 6 bars
params = (('period', 6),)

def __init__(self):
    self.addminperiod(self.params.period)
    self.line.custom_line =[0.0] * self.data.close.buflen() # => filled with 'nan's when accessed in a strategy