Ninjascript basic

[fff222]

Can Ninjatrader suggest a good place to start learning ninjascript? What does "e." mean as in
if (e.MarketDataType == MarketDataType.Last)
Print("Last = " + e.Price + " " + e.Volume);
?
I know it may be a very simple question but it is really difficult to search for the meaning of "e." for one who doesn't know the right place. Thank a lot if anyone could help.

[NinjaTrader_Brett]

Hello,

Thanks for your note.

Actually e.MarketData is getting into some more advanced NinjaScript and programming.

Please check out the following page for infomration on this:

http://www.ninjatrader.com/support/helpGuides/nt7/marketdataeventargs.htm

You can see for the method OnMarketData(MarketDataEventArgs e) we assign the input data the variable of e here. Then we use e in our OnMarketUpdate to reference the inputted data. If you changed the letter here in the parameter constructor you would need to use a different letter.

For example:

OnMarketData(MarketDataEventArgs d)


Now I would need to use d.MarketData if I choose not to use the standard e for whatever reason.


Let me know if I can be of further assistance.

[fff222]

Thanks a lot for your answer. It is very helpful indeed.

As in the guide

protected override void OnMarketData(MarketDataEventArgs e)
{
// Print some data to the Output window
if (e.MarketDataType == MarketDataType.Last)
Print("Last = " + e.Price + " " + e.Volume);
else if (e.MarketDataType == MarketDataType.Ask)
Print("Ask = " + e.Price + " " + e.Volume);
else if (e.MarketDataType == MarketDataType.Bid)
Print("Bid = " + e.Price + " " + e.Volume);

I'm a bit confused by the meaning of the above. Does it means that the varibale e can either be last/ask/bid (or to say there are three marketdatatype?) , depending on the incoming data? So the data we received from OnMarketData update is something like
Bid-Price-Volume
Bid-Price-Volume
Ask-Price-Volume
etc..
Somewhat like what we saw in time and sales windows?

Do you think there are some simple indicators that one may start studying ninjascript from them? I am curious about how one can write an indicator comparing the performance of two reference assets, for example a particular stock and ES mini intraday. Is it possible in Ninja?

[NinjaTrader_Brett]

Hello,

Yes this is possible, e is actually not just a variable as it hold many arguments. Such as Ask, Bid, last, Volume, Time to name a few. What you mention should be possible if I understand you correctly.

An example of using OnMarketData() in use would be here:

http://www.ninjatrader.com/support/forum/showthread.php?t=3478

More samples here:

http://www.ninjatrader.com/support/forum/showthread.php?t=3220

Let me know if I can be of further assistance.