This indicator is a ported MQL5 indicators from http://www.mql5.com/en/code/1518
Formulas:
SW[i]=(ln((1+Value[i])/(1-Value[i]))+SW[i-1])/2, where
ln - natural logarithm,
Value[i]=(((Median price[i] - MinP)/(MaxP-MinP)-0.5)+Value[i-1])*2/3,
MinP, MaxP - minimum and maximum prices in the range from (i-Period) to i.
Download:
The indicator was revised and updated