Logic Problem?

[DaveS]

Can anyone tell me why this does not work? It never prints an arrow.

protected override void OnBarUpdate()
{
if (Low[0] < Low[1]) // Problem is in this line.
{
DrawArrowUp("Up" + CurrentBar, false, 0, Low[0] - (1 * TickSize), Color.Blue);
}
}

I know the problem is in the 'if' statement, if I change it to

if (Close[0] >= Median[0])

It prints arrows correctly.

Thanks
Dave

[noevictorian]

Dave,

I was about to post a near identical question to the board when I saw your post from today. I'm having the same problem with simple logic. My code is as follows:

double myInteger = Close[1];
if (Close[0] > myInteger)
{
Plot0.Set(100);
} else {
Plot0.Set(0);
}

My code is actually a modified thing that I did during troubleshooting but you'll see that the problem boils down to the same thing...

Comparing basic OHLC data between two bars when one references a historic value.

Close[0] > Close[1]

Just like you... if I do something like Close[0] = Open[0], it works. But once I reference a [1] or [2], it breaks.

This seems so fundamental that I feel like an idiot for not figuring it out. But I'm glad to know that I'm not alone and there's clearly some trick we're both missing.

[DaveS]

I went through the same agony. It seemed so simple that I thought I must be doing something stupid.

Hopefuly someone will have the answer.

[noevictorian]

In case any NinjaTrader admin reads this thread and wants to chime in... here's the simplest demonstration of the problem I could think of:

If you follow Lesson 1 from the NinjaScript help tutorials you create an indicator that draws a line every time the close price = the open price. The code is this:

protected override void OnBarUpdate()
{
Plot0.Set(Open[0] == Close[0] ? 1 : 0);
}

If all you do is change it to this:

protected override void OnBarUpdate()
{
Plot0.Set(Open[0] == Close[1] ? 1 : 0);
}

The whole thing fails to plot. No errors come up. And it compiles successfully... just is a blank plot on the chart.

[NinjaTrader_JoshP]

Errors do come up with those codes you guys are using. You will see it in the Control Center log. Please see this tip on what needs to be done: http://www.ninjatrader-support2.com/...ead.php?t=3170

[DaveS]

So there you go Noevictorian, we WERE doing something wrong.

Thanks very much Josh, that fixed it.