object reference not set to instance of an object

[Stopped]

Hello,

I have the following custom method:

privatebool IsTrough(IDataSeries price, int endBarsAgo)
{
if (CurrentBar - endBarsAgo < 2)
returnfalse;

if (price[endBarsAgo + 1] < price[endBarsAgo])
{
for (int i = 2; i <= CurrentBar - endBarsAgo; i++)
{
if (price[endBarsAgo + i] == price[endBarsAgo + 1])
continue;
elseif (price[endBarsAgo + i] > price[endBarsAgo + 1])
returntrue;
elseif (price[endBarsAgo + i] < price[endBarsAgo + 1])
returnfalse;
}
}

returnfalse;
}

When I run MRO(delegate{return IsTrough(lPrice, 0);}, 1, CurrentBar) sometimes I get the error message in the title of this thread.

Do you know what am I doing wrong?

Thanks in advance,

Stopped

[BankRobber]

"object reference not set to instance of an object" error occurs usually when you're trying to access dataseries which has not yet been initialized

[Stopped]

Thank you BankRobber.

Does anyone, particularly from NT support, know why I am getting this error on this particular example when using the MRO function while calling my custom method?

Thanks again beforehand.

[NinjaTrader_Bertrand]

Stopped, I would not see an obivous issue with the code, you would need debug your method / MRO call of it to see where it could run into accessing the null object.

[Stopped]

Hi Bertrand,

I have checked the code and it looks as if the error happens when the MRO function is searching for the 'true' condition in the first few (normally 0 to 2) bars, as the IsTrough method needs 3 bars to generate a result.

Can you think of a line of code I can add to the custom method to deal with 'null' references (i.e. to produce a 'false' rather than an error message)?

Thank you again,

Stoppped

[koganam]

Hi Bertrand,

I have checked the code and it looks as if the error happens when the MRO function is searching for the 'true' condition in the first few (normally 0 to 2) bars, as the IsTrough method needs 3 bars to generate a result.

Can you think of a line of code I can add to the custom method to deal with 'null' references (i.e. to produce a 'false' rather than an error message)?

Thank you again,

Stoppped

It does look as if your code needs at least 3 bars. Therefore, you may want to change your first line to read:

if (CurrentBar - endBarsAgo < 3)

Maybe less elegant, but more robust would be to simply escape the first three bars in OnBarUpdate(), using a sledge hammer to obviate the problem so to speak, as nothing will be called until you have 3 bars on the chart.