Adaptation of Kıvanç Özbilgiç's Turtle Trade PineScript

Oops - I pasted this into my public published chart, so here it goes again.

Here's my first shot at learning PineScript. I have adapted Kıvanç Özbilgiç's Turtle Trade PineScript :
tr.tradingview....cript/pB5nv16J/?utm_source...

I've also added an 83-year semi-log detrended SP500 index, which is explained at :
www.billhowell.ca/ec...detrended price.html