Combining Exponential And Volume Weighting

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//  Copyright by HPotter v1.0 29/08/2014
// The related article is copyrighted material from Stocks & Commodities 2009 Oct 
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study(title="Combining Exponential And Volume Weighting", overlay=true)
length = input(22, minval=1)
xMAVolPrice = ema(volume * close, length)
xMAVol = ema(volume, length)
nRes = xMAVolPrice / xMAVol
plot(nRes, color=blue)