obv = cum(change(src) > 0 ? volume : change(src) < 0 ? -volume : 0*volume)
obv2 = cum(sign(change(src)) * volume )
obv and obv2 return different results
ta.obv(df['close'], df['volume']) returns the same result as obv2
I will also need the return value of obv calculation with talib
Thanks in advance for your help.
I've added an OBV indicator to TradingView, opened it's sources and found
obv = ta.cum(math.sign(ta.change(src)) * volume)
Then I cloned the indicator and replaced this line with
obv = ta.cum(ta.change(src) > 0 ? volume : ta.change(src) < 0 ? -volume : 0*volume)
And added it as a second indicator. I've got a different results. But also I've got a warning:
line 9: The function 'ta.change' should be called on each calculation for consistency. It is recommended to extract the call from the ternary operator or from the scope
So, I replaced the line with
c = ta.change(src)
obv = ta.cum(c > 0 ? volume : c < 0 ? -volume : 0*volume)
And got exactly the same results as original OBV!
So your code for obv is incorrect and you shall google for explanation of this warning. For example: The function should be called on each calculation for consistency, console output?