Polynomial Extrapolation problem

[ctolson]

Hello

In the following VI, the data is to read a voltage, convert it to a pressure (by means of a calibration curve), and display the results on the chart and indicator box.  The voltage input works fine, but when I use the polynomial interp/extrap, the result is NaN.  I have already created a VI to use a linear curve, and that one works fine.  The input spreadsheets were generated by a separate VI used to calibrate the system.  I would appreciate any help in this area.

[Brinoceros]

Hi ctolson,

There could be a number of reasons for the VI to return NaN (often the length of the X input is not equal to the length of the Y input).  I recommend you add error handling because this VI does return helpful error codes.  You can do this by using the Error Cluster From Error Code.vi and Simple Error Handler.vi as seen in the attached image.  This will produce helpful error messages to give you an idea of what is going wrong.

I hope this helps!