Sylvain Vervoort's Asymertical RSI indicator is described in October 2008 issue of Stocks & Commodities.
The formula of this implementation is taken from VT Trader implementation described here:
http://forum.vtsystems.com/index.php?showtopic=9941
Compare ARSI and RSI indicators on the snapshot below:
Download the indicator:
The indicator requires Wilders moving average indicore, so, please, download it using the link below and then install before using SVE_ARSI indicator. Wilders Moving Average