Using the LinReg Indicator with Mathematical Operators on the Source/Input Series

[beejinator]

Hello,

I am attempting to replicate an indicator I have used on other platforms. I am getting an error on one portion of the code when attempting to compile. The error seems to be related to the LinReg indicator/function.

The indicator is named Squeeze Momentum Indicator in the Ninjatrader public library, and it attempts to mimic the TTM Squeeze from Thinkorswim. This iteration seems to have been taken from Tradingview Pinescript. The LinReg function is used to plot the histogram of the indicator.

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Thinkorswim Thinkscript Code (Inertia is the Thinkorswim version of LinReg):

def K = (Highest(high, length) + Lowest(low, length)) / 2 + ExpAverage(close, length);
def momo = Inertia(price - K / 2, length); <<<< histogram values

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Tradingview Pinescript Code:

K = (highest(high,length) + lowest(low,length)) / 2 + ema(close,length)
Momo = linreg(source-K/2,length,0) <<<< histogram values

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Ninjatrader Code that isn't working:

double h = High[HighestBar(High, LengthKC)];
double l = Low[LowestBar(Low, LengthKC)];

// calculate Value
data[0] = Close[0];
double ema = EMA(data,LengthBB)[0];
double avg = ((h + l) / 2) + ema;

IsSqueezes[0] = 0.0;
SqueezeDef[0] = LinReg(data[0]-avg/2,LengthBB); <<<< histogram values

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I've attached a screenshot of the bulk of the code in Ninjatrader, which also includes the error codes that have been generated. It looks like LinReg might require the 'series' data type in the first input (second screenshot attached), so I'm not sure how to proceed here, but there must be a way to do this if other similar trading applications can manage it.

Any help would be much appreciated!!

Thank you

[NinjaTrader_Kate]

Hello beejinator,

Thank you for your note.

I note that you're not accessing the actual indicator value for the LinReg at 111. You have the following:

SqueezeDef[0] = LinReg(data[0] - avg/2, LengthBB);

And you should have the following instead:

SqueezeDef[0] = LinReg(data[0] - avg/2, LengthBB)[0];

Does making that change rectify the compile error?

Thanks in advance; I look forward to assisting you further.

[beejinator]

Thanks Kate! I did actually try that, below is a screenshot using that version. I think it's having a problem with me calculating the LinReg input as a "series<double>" minus a "double", specifically the subtraction, instead of just using a series<double> by itself for the input.



I also tried it using just the "data" series, without the [0] on the end, and received this slightly different error about using a subtraction operation:

[NinjaTrader_Kate]

Hello beejinator,

Thank you for your reply.

I think you need to save your calculated value to a custom series first:

// instantiate series at class level
private Series<double> myCustSeries;

//in State.DataLoaded
myCustSeries = new Series<double>(this);

// in OnBarUpdate
myCustSeries[0] = data[0] - avg/2;
SqueezeDef[0] = LinReg(myCustSeries, LengthBB)[0];

I would give that a try there and see if that works better for you.

[beejinator]

This worked! You're a genius! Thank you so much!