CMO Oscillator with Filter

////////////////////////////////////////////////////////////
//  Copyright by HPotter v1.0 19/04/2014
// This indicator plots a CMO which ignores price changes which are less 
// than a threshold value. CMO was developed by Tushar Chande. A scientist, 
// an inventor, and a respected trading system developer, Mr. Chande developed 
// the CMO to capture what he calls "pure momentum". For more definitive 
// information on the CMO and other indicators we recommend the book The New 
// Technical Trader by Tushar Chande and Stanley Kroll.
// The CMO is closely related to, yet unique from, other momentum oriented 
// indicators such as Relative Strength Index, Stochastic, Rate-of-Change, etc. 
// It is most closely related to Welles Wilder`s RSI, yet it differs in several ways:
// - It uses data for both up days and down days in the numerator, thereby directly 
// measuring momentum;
// - The calculations are applied on unsmoothed data. Therefore, short-term extreme 
// movements in price are not hidden. Once calculated, smoothing can be applied to the 
// CMO, if desired;
// - The scale is bounded between +100 and -100, thereby allowing you to clearly see 
// changes in net momentum using the 0 level. The bounded scale also allows you to 
// conveniently compare values across different securities.
////////////////////////////////////////////////////////////
fFilter(xSeriesSum, xSeriesV, Filter) =>
    iff(xSeriesV > Filter, xSeriesSum, 0)

study(title="CMOfilt", shorttitle="CMOfilt")
Length = input(9, minval=1)
Filter = input(3, minval=1)
TopBand = input(70, minval=1)
LowBand = input(-70, maxval=-1)
hline(0, color=gray, linestyle=line)
hline(TopBand, color=red, linestyle=line)
hline(LowBand, color=green, linestyle=line)
xMom = close - close[1]
xMomAbs = abs(close - close[1])
xMomFilter = fFilter(xMom, xMomAbs, Filter)
xMomAbsFilter = fFilter(xMomAbs,xMomAbs, Filter)
nSum = sum(xMomFilter, Length)
nAbsSum = sum(xMomAbsFilter, Length)
nRes =   100 * nSum / nAbsSum
plot(nRes, color=blue, title="CMOfilt")