Trend identification, as bullish and bearish territories with this indicator, made of a 55 periods Triangular Moving Average shifted with its 21 previous value.
A small band is made of 2 over TMA plus and minus factorized ATR value.
//parameters
// fact = 0.13
// p = 55
// s = 21
a = TriangularAverage[p](close)
b = a[s]
atx = AverageTrueRange[13](close)
factor = atx * fact
hh = b + factor
l = b - factor
Return b AS "55 TMA MID", hh AS "55 TMA HIGH", l AS "55 TMA LOW"