Trend Analysis Index Backtest

In essence, it is simply the standard deviation of the last x bars of a
y-bar moving average. Thus, the TAI is a simple trend indicator when prices
trend with authority, the slope of the moving average increases, and when
prices meander in a trendless range, the slope of the moving average decreases.

You can change long to short in the Input Settings
WARNING:
- For purpose educate only
- This script to change bars colors.