Chapter 9(Core ML) -No green rectangle appears after building

[ihappyfish]

hi, I might need your help when learning Chapter 9 (Core ML)
After I followed instructions through page 186, no green rectangle appears after building both on iOS Simulator and on my iPhone 6s plus.
Actually, it works just well before I upgraded to Xcode GM and High Sierra 10.13 GM Candidate.
My current environment:
iOS 11 GM
iPhone 6s Plus
Xcode 9 GM
macOS High Sierra (10.13 Beta -17A362a)

So could you please help me to solve this problem?
Thanks a lot.

[mkatz]

I’d double check that drawDebug is set to true. If it is, take a look at the drawPoints and see if it has reasonable values. If not we’d have to look back and see where the region is miscalculated, and if it the points are good, look into drawing method.