Market Facilitation Index (MFI)

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//  Copyright by HPotter v1.0 10/06/2014
// The Market Facilitation Index is an indicator that relates price range to 
// volume and measures the efficency of price movement. Use the indicator to 
// determine if the market is trending. If the Market Facilitation Index increased, 
// then the market is facilitating trade and is more efficient, implying that the 
// market is trending. If the Market Facilitation Index decreased, then the market 
// is becoming less efficient, which may indicate a trading range is developing that 
// may be a trend reversal.
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study(title="Market Facilitation Index (MFI)", shorttitle="MFI")
xmyVol = volume
xmyhigh = high
xmylow = low
nRes = (xmyhigh - xmylow) / xmyVol
plot(nRes, color=green, title="MFI", style = histogram)