CrossAbove() giving different results

[Locke]

Hi again guys. I'm getting some weird behavior using two different parametrizations of CrossAbove() and I just want to make sure I'm not missing anything.

From the docs:
CrossAbove(IDataSeries series1, double value, int lookBackPeriod)
CrossAbove(IDataSeries series1, IDataSeries series2, int lookBackPeriod)

I've been using
CrossAbove(Close, bollinger.Upper,1) and everything has been alright.

However, I want to have a variable modify the bollinger.Upper series value, so I tried switching from the IDataSeries object to a double by using

CrossAbove(Close, bollinger.Upper[0], 1) , with the intention of then modifying bollinger.Upper[0] with some other doubles.

But when I ran two separate backtests on the same data series (verified) on multiple different sets, I get different trade results... huh? Not drastically different mind you, something like 1426 trades vs 1405 trades, but I'm just surprised there is ANY difference.

Either it's a quirk in the CrossAbove function how it handles the two different data types, or I checked versus two different data sets (verified I didn't do this), or it's a cosmic mystery. Anyone seen something like this before?

[NinjaTrader_CalH]

Hello Locke,

Thank you for your post.

The difference here is that you would be comparing a Static value (double) to a Dynamic value (IDataSeries)

With the Static value you are comparing against the same value in both the current bar and previous bar (Previous bar is used to check for the cross portion)

With the Dynamic you are comparing the current bar of each series to the previous bar for each series

Static -

if(DataSeries[0] > Value && DataSeries[1] <= Value)

Dynamic -

if(DataSeries[0] > DataSeries2[0] && DataSeries[1] <= DataSeries[1])

Let me know if I can be of further assistance.

[Locke]

Argh, that's right it's based off the previous bar. I'm a dope. Thanks for the clarification Cal.