"DemandIndex" (Financial Indicator)

Commonly abbreviated as DI. Is a momentum indicator. Was developed by James Sibbet.
Takes two parameters: n for the periods of moving averages and c, a threshold constant.
Is computed using the closing prices and volumes.
Returns one time series that is constructed to contain values between and .
FinancialIndicator["DemandIndex",n,c] uses period n moving averages and threshold c.
The first value in the time series after periods.