Projection Bands

[eleven]

Hello,

I'm trying to code Projection Bands by Mel Widner and I need some help. Can anyone help me to see what I'm doing wrong? I will attach my file and below is the code I'm trying to convert into a NT7 indicator. Thanks, eleven

SlopeHigh = LINEARREGRESSIONSLOPE[n](high) 
SlopeLow = LINEARREGRESSIONSLOPE[n](low)   

UpProjBand = high 
LoProjBand = low  

FOR i = 1 TO n      
   UpProjBand = MAX(UpProjBand, high[i] + i * SlopeHigh)      
   LoProjBand = MIN(LoProjBand, low[i] - i * SlopeLow) 
NEXT

**** Updated **** I've attached the fixed code for ProjectionBand indicators.

[NinjaTrader_ChelseaB]

Hello eleven,

When you mention you are doing something wrong, what is the wrong behavior?

Are you getting a compile error?

Are you getting a run time error?

If so, what is the error message?

Are you getting a different calculated value than expected?
What is the incorrect value?
What is the expected value?

[eleven]

Hello, On every OnBarUpdate(), "UpProjBand" and "LoProjBand" is reset to 0. How can I pass the previous bar "UpProjBand/LoProjBand" to the for statement? I'm stuck. Can you point me in the direction on how to code this? Thanks, Tom

            if (CurrentBar < Period)
                return;
            
            double SlopeHigh = LinRegSlope(High, Period)[0];
            double SlopeLow = LinRegSlope(Low, Period)[0];
            
            double UpProjBand = 0; double LoProjBand = 0;
            for (int i = 0; i < Period; i++)
            {
                UpProjBand = Math.Max(UpProjBand, High[i] + (i + 1) * SlopeHigh);
                LoProjBand = Math.Min(LoProjBand, Low[i] - (i + 1) * SlopeLow);            
            }
            
            PBU.Set(UpProjBand);
            PBL.Set(LoProjBand);

[NinjaTrader_ChelseaB]

Hello eleven,

Please try printing the values that you are setting this plot to.
Print(string.Format("{0} | {1} | {2}", Time[0], SlopeHigh, SlopeLow));

The LineRegSlope indicator returns a value that is between 0 and 1.

[eleven]

Hi Chelsea,

I think I will need to convert "UpProjBand" and "LoProjBand" to a custom dataseries to accomplish what I need.

This is the issue...it passes 0 in the for statement rather than using last calculated.

            double UpProjBand = 0; double LoProjBand = 0;

eleven

[NinjaTrader_ChelseaB]

Hello eleven,

With the code:
LoProjBand = Math.Min(LoProjBand, Low[i] - (i + 1) * SlopeLow);

You are taking whichever is lower, 0 the initial value of LoProjBand or the calculated value. In this case 0 is always going to be the lower number correct?

[eleven]

Chelsea,

That is correct. I want to pass the last value and not 0. I just don't know how I would go about programming it. Does UpProjBand need to be a custom dataseries?

Thanks,

eleven

[NinjaTrader_ChelseaB]

Hello eleven,

I'm not quite certain that I understand.

The code you have written I am referring to, will always produce a 0 or a negative number.

You are using Math.Min(). Math.Min will return which ever number is lower. You are supplying 0 and a number greater than 0. This means 0 will always be returned because this is a lower number.

I'm not quite certain how you would add a data series here or what this would be used for. Can you further describe how you would use this?

[eleven]

I think I know what I did wrong. I will have another try at it later today.

Thanks for your reply.

eleven