When doing tests, does anyone change the number of initial candles to store? I took the H1 data from the last 5 months at BitcoinCharts (3570 candles), changed the format to what the backtester expects and tried this:
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I'm wondering if there's really a need to change that setting or not. Note the huge change from 200 to 300 candles.
I am looking in to the data as to what kind of difference this makes, but do note:
The EMA method is supposed to start out with a history, the ideal case would be the complete history but since this is not practicle (and the difference decreases exponentially as you remove old history). If you don't start with a big history you aren't using pure EMA as you are not able to calculate the real EMA (a number which is built up using the complete history). Diabolicus showed the EMA difference in EMA calculation between a big and a small history.
If you are looking at the profit as a result of different histories you are just comparing different kind of EMAs (different levels of pure EMA so to say) which each other. It may the case that an EMA without an history would be the most profitable in a backtest, but it pretty hard to turn that into conclusions.
Hope that this explanation makes sense.
Hi, thanks for taking the time to reply! Let's see if I'm getting everything right. When you say "a different history" you mean to say that when I change the number of candles to retain for calculation, I'm basically evaluating a different timeframe = different history, correct?
On another note, I was looking through the source code to see if I could write a tester that would automatically find the optimum EMA values for a given timeframe, but I haven't had much time to do so.