Wonky curves[img]data:image/png;base64,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

Did you see the picture I posted?  I'm not sure that my technique was correct, and I don't see it in this thread.  Can I post a word doc inn this forum?  Guess I need coaching on how to post a picture.

Thx, pjl

Good point.  As another test, I have generated a set of polar files with minor changes with only the original input points, i.e. heading, wind speed and boat speed.  When I examine the polar edit function in Expedition, I can still see wonky curves.  I can eliminate the wonky curves by editing the displayed plot, which seems to change the data in the array of data in the original polar selected for examination.  This raised my question of how the program works.  Meaning does the optimization process use the data from the smooth curve formula that seems to be generated by a curve fitting process to the plotted data.  Does that make sense?  Maybe Nick will add some knowledge to this thread that will eplain what's going on.  Thx, pjl

iterative edits solved my problem.  I've got a clean and rational polar now!!

Where can I find nourishment understanding the edit of polar files to improve accuracy of the basic polar file?  I have explored the operation and find I still lack understanding of how the edit changes to the polar graphic display interacts with the base text file.  It looks like a powerful connection, but I keep screwing up the base file, getting changes to the data that I don't understand.  Nick, can you please comment?
Thx, pjl