Help using MAX

[wcmaria]

I am trying to create an indicator that will plot a down arrow above a bar if certain conditions are met.

Right now I am trying to identify if the current bar has a high that is higher than the previous 4 bars.

My logic looks like this

var2 = MAX(High, 3)[1];

if (High[0] > var2)
var3=1;
else var3=0;

if (var3==1)
DrawArrowDown("tag1" + CurrentBar, true, 0, High[0] + TickSize, Color.Red);

when I compile the indicator I get no plots on the screen.
if I change the MAX(High,3)[0] and the if(High[0} == var2) it works.

I can't seem to figure out why MAX(High,3)[1] doesn't work. Should this not contain the highest bar price for the last three bars beginning one bar ago? Therefore I am checking if the current bar high is greater than the highest high of the previous 3 bars.

[sledge]

Does this help?

http://ninjatrader.com/support/forum/showthread.php?t=13924

[NinjaTrader_ZacharyG]

Hello wcmaria,

Thank you for writing in.

When your indicator wasn't plotting, did you see any errors in the Log tab of the Control Center or the Tools -> Output Window?

You'll want to ensure that you have enough bars before plotting. I see that your indicator is attempting to access the previous value of the MAX() indicator. If no data exists one bar ago, you will run into a run-time error and the indicator will not plot.

I would suggest taking a look at this tip post on our support forum about more information on making sure that you have enough bars in the data series you are accessing: http://ninjatrader.com/support/forum...ead.php?t=3170

Please, let us know if we may be of further assistance.

[wcmaria]

No arrows are plotted on a 5 minute chart with at least a days worth of bars.

In the output window I get the following error:

Error on calling 'OnBarUpdate' method for indicator 'aahilo' on bar 0: You are accessing an index with a value that is invalid since its out of range. I.E. accessing a series [barsAgo] with a value of 5 when there are only 4 bars on the chart.

Here is my code.

protected override void OnBarUpdate()
{
min = MIN(Low,4);
max = MAX(High,4);

bool buyCond1 = Low[0]<min[1];
bool buyCond2 = Close[0]>Open[0];
bool buyCond3 = Close[0]>Close[1];

bool sellCond1 = High[0]>max[1];
bool sellCond2 = Close[0]<Open[0];
bool sellCond3 = Close[0]<Close[1];

if (buyCond1 && buyCond2 && buyCond3)
{
DrawArrowUp("tag1" + CurrentBar, true, 0, High[0] + TickSize, Color.Blue);
}

if (sellCond1 && sellCond2 && sellCond3)
{
DrawArrowDown("tag1" + CurrentBar, true, 0, High[0] + TickSize, Color.Red);
}
}

[NinjaTrader_ZacharyG]

Hello wcmaria,

Please note that your script will call OnBarUpdate() on every bar.

On the first bar, there is no previous bar to look back to. You need to add a check to prevent accessing a non-existent previous bar, per my previous post:

I would suggest taking a look at this tip post on our support forum about more information on making sure that you have enough bars in the data series you are accessing: http://ninjatrader.com/support/forum...ead.php?t=3170

Please, let us know if we may be of further assistance.

[wcmaria]

Thanks.

Used the following code and it worked.

if (CurrentBar < quality)
return;