Basics :
The Force Index (sometimes referred to as “the index”) is another technical analysis concept introduced by Alexander Elder in his book Trading For A Living.
The calculation for the force index:
Force Index (1) = [Close (current period) – Close (prior period)] x Volume
Force Index (13) = 13-period Exponential Moving Average of Force Index (1)
A 13-period average highlights short-term trends, and is suitable for shorter-term traders. A 100-period Force Index average will highlight longer-term trends and is preferred by longer-term traders.
This version :
In this version we are using well known JMA (Jurik Moving Average) instead of using the EMA for calculation