IAM Profile - only 9 points?

[iopalinsky]

Why are we limited to just 9 points for a custom IAM profile? Creating an IAM profile with just nine points seems to be a little buggy, and can result in some funky curves, even if the chosen points are valid point on the IAM curve.

[André Mermoud]

PVsyst performs a cubic interpolation between points. That is, for a value situated between point #2 and #3, it adjusts a cubic function on the points #1, #2, #3, #4.

This allows to represent quite well a curved profile, especially a smooth one like the IAM behaviour. 9 points are largely sufficient in this case.

However in some cases the "external" point (#1 or #4 in my previous example) gives artefacts like in your example.

You can avoid this by displacing the point #8 to a higher angle value (and lower IAM value), or suppress one of the points #4 or #5 (which are quasi useless) and add a point between #8 and #9.