Hi swh
Sorry, I was a bit rushed with my last response. I was commenting on your statement of: "That to me looks like the coding inside 55LOC is wrong, should be -3.0º" (which I agree with from what you have shown). I was wondering whether some manual data input was involved (unlikely, I know) and a gradient of 5.3%, which equates (roughly) to 3° was copied and pasted in error, just a thought.
Cheers
TeeS