Avoiding Curve fitting

Discussion in 'Automated Trading' started by maninjapan, Dec 10, 2009.

  1. Code7

    Code7

    No, it doesn't make sense. QQQQ went up from 29.27 to 47.49 in the testing period. Please provide full disclosure of your analysis and please be very specific. Put up or shut up.

    I'll go first. I used daily QQQQ data from TradeStation and this code for my test.
    Code:
    Inputs: Num(1);
    Vars: EP(0);
    
    if CurrentBar = Num then
    	Buy next bar on Open;
    
    if CurrentBar = Num + 1 then
    	EP = Open;
    
    if CurrentBar > Num then
    begin
    	Sell next bar at EP * 1.07 Limit;
    	Sell next bar at EP * 0.93 Stop;
    end;
    
    I raised Num from 1 to 2000 by 1 to buy on all days and then looked up the results by sorting the optimization report. So in essence, I just weighted all days equally without any bias whatsoever. Random entries will average to the same winning %.

    I verified the results of the above code by comparing against the built-in SetProfitTarget and SetStopLoss. Almost identical outcome, winning % very close to 60. I also accounted for the MaxBarsBack value and made sure my first trade was on 05/07/2002.

    Unlike the built-in TS stop and target, the above code doesn't exit on the entry day. However, the difference in results was minimal due to a total sample size of > 1500. We are talking about different winning % of +- 0.5 points here.

    I'm very interested to learn how you got slightly better than 50 and not 60.
    Beyond that, your twisted drivel and bizarre claims are not worth discussing.
     
    #111     Jan 6, 2010
  2. Jerry030

    Jerry030

     
    #112     Jan 6, 2010
  3. What software have you used to calculate predictive coefficients? Is there a name for this calculation or is it an umbrella term for regression, forecasting, classification, etc, combined with cross-validation?

    Data mining software poll:
    http://www.kdnuggets.com/polls/2009/data-mining-tools-used.htm
     
    #113     Jan 6, 2010
  4. Jerry030

    Jerry030


    Like a good carpenter I use a fair number of software tools. Of those listed I occasionally use Rapid Miner and S-Plus. I also use a number of others. What you are looking for in a NN application is the ability to rank the final weights given to each input variable. In general terms this can be done by systematically varying the values of the independent variables and measuring their contribution to the output signal
     
    #114     Jan 6, 2010
  5. ROFLMAO!

    I just thought you may be just a kid playing around with a computer and a language you do not understand how it works. You also appear vicious and insulting when confronted and you seem to totally miss the essence of the points made. I suggest you first learn EL before exposing yourself. It is clear to me now you are not a trader. So long.
     
    #115     Jan 7, 2010
  6. Code7

    Code7

    Looks like you decided to not put up and fully disclose how you
    Probably because you are a liar.

    You also gave not a single valid reason why my winning percentage of 60.5 +- 0.5 points was allegedly not accurate. Just some more useless drivel without any substance or content.
     
    #116     Jan 7, 2010
  7. Yes this is what happened when I got the fools gold. I was normalizing the inputs to a span of zero to one to make it more suitable for the NN models I was using. I was doing that by creating a normal distribution of my test window, which involved getting a mean and standard deviation.

    The two flaws:
    1. I screwed up the call to calculate the standard deviation; the way it worked was counter-intuitive to how I thought I was supposed to give it stuff.
    2. I calculated the mean of the entire backtest window up front, when it should have been a rolling window. I failed because I was incorporating future information into the mean.

    With those two errors, the neural network was able to take the crap indicators and make something out of them. Something that wouldn't forward test, but something that wasn't 100% perfect yet portrayed ridiculous returns.
     
    #117     Jan 7, 2010
  8. Liar? Another insult? Does your mom know you are insulting people using her computer while she is working trying to feed you?

    Listen to me. You do not understand how EL works. I have no time posting results to educate you. What you have done is program a trend following system. It is reasonable that you will get a winning bias since there was a trend, but only in hindsight. The system you are attemtping to compare it to was a position/swing trading one. You are comparing apples and oranges. I have come accross many like you before. Your "know it all" attitude and autistic behavior is probably due to a well-known syndrome:

    http://en.wikipedia.org/wiki/Asperger_syndrome

    ROFLMAO!

    P.S. Thinking about it now, what you have done is to prove that the APS system did as well as a trend following system. Actually, you proved that the pattern system was as good as a system developed in hindsight that followed the trend but did so unconsciously due an erroneous application of EL.
     
    #118     Jan 7, 2010
  9. You are wasting your time responding to bashatrader, an exceptionally moronic poster even by ET standards.

    Put him on ignore.
     
    #119     Jan 7, 2010

  10. The crossdresser is moaning at himself
     
    #120     Jan 7, 2010