Bollinger Bands on a Rate of Change indicator?

[ollywedgwood]

Hi!
Please could anyone help - I'm trying to modify the ROC indicator so that it also has Bollinger bands about the ROC line.
Any pointers/code suggestions gratefully received!!
Thanks
Olly

[NinjaTrader_JoshP]

Value.Set(((Input[0] - Input[barsAgo]) / Input[barsAgo]) * 100);

Change Input to your bollinger indicator. http://www.ninjatrader-support.com/H...Bollinger.html

[ollywedgwood]

Thanks Josh - I see what you mean, using the Value.Set to pass in to the Plot0 output.
The ROC line comes out fine, but I would like to plot the Bollinger Bands around the ROC itself, rather than price. Is this possible?

[NinjaTrader_JoshP]

You would then need to modify the Bollinger indicator to use ROC instead of price as its input.

[ollywedgwood]

Ah - great! Any ideas how I would do this in principle - I've been looking at the Bollinger indicator code:

Upper.Set(SMA(Period)[0] + NumStdDev * StdDev(Period)[0]);
Middle.Set(SMA(Period)[0]);
Lower.Set(SMA(Period)[0] - NumStdDev * StdDev(Period)[0]);

...but it is using SMA and StdDev indicators which use price data. How could ROC be put in place of price? Thanks again.

[NinjaTrader_JoshP]

Olly,

I would not know how you would want to change the math of it. You will just have to investigate the indicators and change the parts that you feel need to be changed. StdDev is also an indicator that you can change to reflect ROC.

[ollywedgwood]

Ok, just a thought here - I've tried this:

// find the average and std of ROC
double average = SMA(ROC(), Period)[0];
double std = StdDev(ROC(), Period)[0];


Upper.Set(average + NumStdDev * std);
Middle.Set(average);
Lower.Set(average - NumStdDev * std);


Value.Set(((Input[0] - Input[barsAgo]) / Input[barsAgo]) * 100);

...but the compiler doesn't like it - ROC only takes 1 overload? However, it seems to work if I use VOL() instead of ROC() for example - I'm not sure why!?

[NinjaTrader_JoshP]

http://www.ninjatrader-support.com/HelpGuideV6/RateOfChangeROC.html

ROC requires parameters.