WSOWROTrend indicator is based on Widners Oscilator.
It is indicator for the calculation of the support and resistance levels. It means not one level. Many S/R levels. This indicator is using some filter system to receive the S/R level with more higher probability. nPeriod is number of the bars for the calculation of the minimums and maximums. The value of nPeriod may be from 3 or above. 9 is by defauld value.
