polynomial fit

Hey guys,.

Need some help here.

I'm a polynomial fit (order 10) for my project. the adjustment takes place between the dielectric constant and the frequency. I made the connection with a block Express Fit and I exported the values in the chart to Excel. The adjustment has been very accurate and the fitted values were very close to the values that I have seen.

I tried to implement the polynomial equation in a node form and checking the values in real-time by changing my independent variable (x) (Di - electric Constant). When I change the input with control, which should match the values exported from the best graphic made (obtained from the poly block made) right?

I tried to change my Di - electric values of 1.4 to 5... Up to a value of 3, the output of the formula node averaged exported graphics best fit values. After 3, the values that I get my formula node are very far from the observed reading...

What is the reason behind this?

Thanks in advance for your help

Attached are the VI and the Excel for your reference.

Hari

Here is a quick sketch. Maybe this can give you some ideas...

(Of course the adjustment should only be restored if data or command changes, so it's rather crude at the moment)

Tags: NI Software

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