I read that too. But I already have Ninja & Tradestation and I hesitate to add Investor RT & IQFeed......
Ninja really needs to improve on this. I heard for NT 7.0 the bid ask isn't usable, I don't remember the details but it's disappointing. This is actually one of the only reasons I keep tradestation..

There is a thread on the Ninjatrader forums about problems people are having with the DTNIQ datafeed: connection lost, Ninjatrader freezing, etc. So going to DTNIQ is not the greatest idea right now.

I am not sure what you mean about bid/ask data in Ninjatrader 7. All of the GOMCD indicators work fine.

Indicators that use Level 2 data from OnMarketDepth() store the data in lists. In NT6.5 you can insert rows into a list without having previously explicitly created those rows. In NT7, if you try to insert a row into a position number higher than the row.Count (the number of rows in the list), or if you try to read data from such a row, you will get a runtime error.

Adding a simple one shot routine to create the required number of rows solves the problem. I posted a code sample:

How to use volume in your trading This seems to work pretty good. Try it and let me know how it works for you! I recommend that you also add error traps to the other major modules of your program, including OnBarUpdate() and any custom Plot() methods you have added. If any methods other …

With NT 7, I'm not sure you can use historical bid/ask data and backfill it. If this is not correct I'd love to know because that would remove any advantage of investor RT. I will ask in the GOM thread.

It's a little awkward but once it is set up, it works very well.

T


//=============================================================================================
//These Lists need to have been declared as variables in the variables region:
//private List<LadderRow> askRows = new List<LadderRow>();
//private List<LadderRow> bidRows = new List<LadderRow>();


protected override void OnMarketDepth(MarketDepthEventArgs e)
{
// try, catch will handle any runtime errors, preventing the program from crashing
try{ // this { is the start of the area that is being monitored for errors
// there may be runtime errors when this starts up in NT7
{

List<LadderRow> rows = null;

// Checks to see if the Market Data is of the Ask type
if (e.MarketDataType == MarketDataType.Ask)
rows = askRows;

// Checks to see if the Market Data is of the Bid type
else if (e.MarketDataType == MarketDataType.Bid)
rows = bidRows;

if (rows == null)
return;

#if NT7 // This switch will prevent the bracketed code from being compiled in NT6.5.
// In NT7, MUST explcitly create list rows before inserting into them, to prevent runtime error
{ // Could also have used the Add method but this is more fun.
if(rows.Count<5) //Create as many rows as you will need for your Level II data. I don't think you can get more than 20 rows of Level 2 data, so 22 rows should be enough.
{ int idx =0;
for (idx = 0; idx < 22/2; idx++)
{ //insert placeholder objects of type LadderRowrows into the list
askRows.Insert(idx, new LadderRow((int)0,(int) 0, ""));
bidRows.Insert(idx, new LadderRow((int)0,(int) 0, ""));
}
}
}
#endif
// In NT7, insertion will fail if there is not already an empty row to insert into


// Checks to see if the action taken by the Ask data was an insertion into the ladder
if (e.Operation == Operation.Insert)
{
//there was a mistake in the next line. The casting of e.price as an integer
//is a mistake that will cause a lot of problems
// was: rows.Insert(e.Position, new LadderRow((int)e.Price,(int) e.Volume, e.MarketMaker));
// should be
rows.Insert(e.Position, new LadderRow(e.Price,e.Volume, e.MarketMaker));
Print("Rowcount, DOM_Bands7 = "+rows.Count);
}
/* Checks to see if the action taken by the Ask data was a removal of itself from the ladder
Note: Due to the multi threaded architecture of the NT core, race conditions could occur
-> check if e.Position is within valid range */
else if (e.Operation == Operation.Remove && e.Position < rows.Count)
rows.RemoveAt(e.Position);

/* Checks to see if the action taken by the Ask data was to update of data already on the ladder
Note: Due to the multi threaded architecture of the NT core, race conditions could occur
-> check if e.Position is within valid range */
else if (e.Operation == Operation.Update && e.Position < rows.Count)
{
rows[e.Position].MarketMaker = e.MarketMaker;
rows[e.Position].Price = e.Price;
rows[e.Position].Volume =(int) e.Volume;
}

// Calling ChartControl.Refresh() will cause the Level II data to update real-time. Adding
// this delay routine will prevent CPU utilization from going through the roof. Setting a
// really high value will effectly delay the update until the next tick arrives which could
// be a really long time is the market is really slow. This may or may not matter to some.




}
} //This is the end of the region that is being monitored for runtime errors
catch (Exception ex){
// Following is what we do if there is an error, sure beats crashing the indicator
Print("Trapped exception in DOM_Bands.OnMarketDepth(): " + ex.Message);
return; //prevents the indicator from crashing
}
}
private class LadderRow //for futures there is no Market Maker, but we can still use this to populate the lists
{
public string MarketMaker; // relevant for stocks only
public double Price;
public int Volume;

public LadderRow(double myPrice, int myVolume, string myMarketMaker)
{
MarketMaker = myMarketMaker;
Price = myPrice;
Volume = myVolume;
}
}
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++==

A few days ago I posted an OnMarketDepth() module modified to work with Ninatrader 7. Please note the correction below. There was one line where I was mistakenly casting e.price as an integer. That causes a lot of problems for instruments whose prices have digits after the decimal points so please don't do it, Putting that in there was a mistake. Sorry for any inconvenience.

Took me a while to notice it because I was doing all my testing on an instrument that actually does have integer pricing.

I found a simple example in the NT Forum (Lot less Code) and this was the one I used in 6.5, but for NT7 caused some performance problems.

Apparently IQfeed (and possibly others) now provide 24 hours historic bid ask data. This makes a huge difference to approaches that rely on vol@bid/ask to guage order flow. It is simply not robust to rely on 24/7 availability of the PC collecting the data. Hopefully we are coming to an age where this sort of analysis can be done much more painlessly. Of course you need tools that can read this and the ability to build a bar tick by tick even from historic data. I hope NT 7.0 doesn't drop the ball on this.

NT7 doesn't store the bid/ask with the data. You can get bid/ask but it's not synchronized with the data.