Re-running script doesn't work

[jpmeyers]

Hello,

I'm a newbie and tried writing a very simple strategy. I am able to successfully write and execute a new strategy using the wizard. However, as soon as try to re-run the script with a new set of parameters, it executes with the original settings I used the first time! Why is that?

Also, I can't seem to get the BarsSinceEntry function to trigger a new purchase. Here are the two conditions I setup using the script wizard:

protected override void OnBarUpdate()
        {
            // Condition set 1
            if (BarsSinceEntry() == BuyPeriod)
            {
                EnterLong(DefaultQuantity, "");
            }

            // Condition set 2
            if (BuyAtStart == true
                && Variable0 != 37)
            {
                EnterLong(DefaultQuantity, "");
                Variable0 = 37;
            }

The second condition is the only way I could figure out how to start the strategy off with a purchase. My intent for the first condition is to trigger a purchase every X days where X = BuyPeriod which is a user entered integer parameter.

Any help would be greatly appreciated!

Thanks,
Frustrated New User

[NinjaTrader_PatrickH]

Hello jpmeyers,

Thank you for your post and welcome to the NinjaTrader Support Forum!

There would need to be a first entry before BarsSinceEntry() would work. Based on the code you provided there is no possible first entry. Your second condition is actually a great way to submit the first entry.

For the strategy parameters can you detail the process you go through to enter the new parameters and re-run the strategy? Are you running the strategy in the Strategy Analyzer?

I look forward to your response.

[jpmeyers]

Patrick,

Thank you for your quick response. I am confused about your answer for BarsSinceEntry(). When I run the sample code, it executes a long entry on the first bar. However, there are no subsequent long entries triggered after the first entry. Why is that? I ran the back test on about one year's worth of daily data, so I would expect to see about 35 long entries based on a BuyPeriod=7 initiation (what I was using to run the script). Here are the results from the trades log:

Trade-#    1
Instrument    VOO
Account    Backtest
Strategy    MySecondStrat
Market pos.    Long
Quantity    1
Entry price    137.98
Exit price    168.21
Entry time    2/2/2013
Exit time    1/18/2014
Entry name    Buy
Exit name    Exit on close
Profit    0.219089723
Cum. profit    0.219089723
Commission    0
MAE    0.012755472
MFE    0.227931584
ETD    0.008841861
Bars    243

And here are the results from the settings tab for the backtest:

Item                     Value
Parameters
BuyAtStart               True
BuyPeriod                7
Data series
Price based on         Last
Type                   Day
Value                  1
Time frame
From                   1/1/2013
To                     1/20/2014
General
Include commission       False
Label                    MySecondStrat
Maximum bars look back   TwoHundredFiftySix
Min. bars required       20
Historical Fill Processing    
Fill type                Default
Slippage                 0
Order Handling
Entries per direction    1
Entry handling           AllEntries
Exit on close            True
Order Properties
Set order quantity       by strategy
Time in force            Gtc

As for the process I use to enter new parameters, here are the steps I take:

1. I first execute the back test by right clicking on the security I want to test (i.e. VOO in the example above) and select "Backtest..."
2. I fill in the parameters as I want them for the test and press the "Run Backtest" button. The first time through, this produces results I expect (except for the confusion above about why additional purchases aren't being triggered).
3. When I want to re-run the backtest, I click on the sideways "backtest" button in the upper right hand corner which re-opens the parameters page with the parameters used the last time I executed the backtest.
4. I then make changes to the parameters I want and press the "Run Backtest" button again. This time, the results don't change and when I look on the settings tab, the settings have reverted back to the values from the first test.

Once again, thanks for your help.

[NinjaTrader_PatrickH]

Hello jpmeyers,

Thank you for your response.

Please attach you strategy to your response so I may investigate this matter further. you will find your strategy in the following directory on your PC: (My) Documents\NinjaTrader 7\bin\Custom\Strategy

[jpmeyers]

Here's the script I was testing...

[NinjaTrader_PatrickH]

Hello jpmeyers,

Thank you for your response.

The reason we only get one entry is because the EntriesPerDirection (http://www.ninjatrader.com/support/h...rdirection.htm) by default is one (1). Even if this is set to two (2) there are only two trades placed on the first day of the test, this is because the BarsSinceEntry is set to == instead of >=. With >= we do not need to use EntriesPerDirection, but it will only base it's entries off the first entry so you may wish to use entrySignalName strings for the entries.

Please let me know if you have any questions.