The PE fuction "Curve" is a good one for a linear interpolation. With regard to the reference, the xi's and yi's should be "numeric constants". Once the curve described by the xi's and yi's were not a fix one, but might be varying based on user's inputs, is there an approach to meet that requirement?
Note that the overall calculation were built on PE, I might need to ask solution within the PE framework.
Thanks in advance!