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Hello everyone,
I am trying to work with Forex data. I would like to do operations on prices. I am still new at Python, and learned that floating numbers give strange results. I am trying to use Decimal to avoid this, but am still getting strange results. At the top of my code I have:
from decimal import Decimal
class myAlgo(QCAlgorithm):
...And within OnData I have:
def OnData(self, data):
self.bid = Decimal(data["EURUSD"].Bid.Close)
self.ask = Decimal(data["EURUSD"].Ask.Close)
self.resultOne = Decimal(self.ask - self.bid)
self.resultTwo = Decimal(self.bid + 0.001)
But these are my results:
bid: 1.0868
ask: 1.08694
resultOne: 0.000140000000000029
resultTwo: 1.0877999999999999
As if I'm still using floats. I am trying to get results of 0.00014 and 1.0878 respectively.
Any help is appreciated.
LE
I'm also going to be doing a lot of comparison operations (> ; >= ; ==) so if working with decimals/ floats is too imprecise/dangerous for this please let me know. Thank you!
Rahul Chowdhury
Hi LE,
In Python, the difference between Decimal, double and float is the level of precision each offers. Decimal is the most precise, with up to 28 significant digits, while float is the least precise, offering up to 7 significant digits. Since most Forex bid/ask prices are precise to 4 decimal places, we can round our Decimals to 4 decimals places using round(number, digits). This will make sure all our operations return numbers with consistent precision because all our prices are equally precise.
Best
Rahul
LE
Thank you Rahul!
Thanks to this information I have simplified my code and forgone the use of Decimals altogether.
LE
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