Fractals ROC Alert

I am playing William's Fractals and got an idea to calculate each fractal's strength by these rules:

- downFractal. FractalROC = (close - lowest(n+1))/(open【2*n】-lowest(n+1))
- upFractal FractalROC = (highest(n+1)-close)/(highest(n+1)-open【2*n】)

And set up a level to filter small fractals.

Bigger FractalROC, Stronger trend