OnRender problem

[turbofib]

protected override void OnRender(ChartControl chartControl, ChartScale chartScale)

// protected override void OnRender(ChartControl chartControl, ChartScale chartScale, ChartBars chartBars)
{
if (CurrentBar < 100) return;
Draw.Line(this, "newLine" + CurrentBar, 5, Low[5], 3, Low[3], Brushes.Red);
return;

}

Ninjascript output :

Indicator 'OnRenderProblem': Error on calling 'OnRender' method on bar 550: You are accessing an index with a value that is invalid since it is out-of-range. I.E. accessing a series [barsAgo] with a value of 5 when there are only 4 bars on the chart.

i don't understand it..why it give me error? the number of Bar is >5....

[NinjaTrader_Jim]

Hello turbofib,

Thanks for opening the thread.

OnRender() is not guaranteed to be in sync with OnBarUpdate() and barsAgo indexes may not be valid references. We have this noted in the OnRender() documentation here:

5. Unlike market data events and strategy order related events, there is NO guarantee that the barsAgo indexer used for Series<T> objects are in sync with the current bars in progress. As a result, you should favor using an absolute index method to look up values (e.g., <series>.GetValueAt(), Bars.GetOpen(), etc)

http://ninjatrader.com/support/helpG.../?onrender.htm

You can reference GetValueAt() and GetLow() below:

GetValueAt() - http://ninjatrader.com/support/helpG...getvalueat.htm

GetLow() - http://ninjatrader.com/support/helpG...-us/getlow.htm