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Equation for polynomial fit


I would like to know how to connect the block on the left with the Polynomial Fit and how to write an equation of fifth order to apply at the Polynomial. Hope for answers. 

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Message 1 of 4

To avoid causing other Forum users a lot of "le Pain" (where "pain" is meant in its English, not French, meaning and pronounciation), please do not submit pictures of code (unless it is a LabVIEW Snippet, which you can learn about by entering "Snippet" into LabVIEW's Help system and reading the "How-To" article).  We need to be able to "poke around" your code to better understand your question.


For example, where in the "block on the left" are the data you want to fit?


Have you read the Help documentation for the Polynomial Fit function?  Do you understand the basis of fitting a function to a series of data points?  Do you know where in your data (it's your data, after all) to find the arrays of X, Y, and Weight?  And if you only have Y explicitly, do you understand the procedure well enough to create X and Weight?


If the answer to any of the above questions is "No", learn a little (more) about fitting functions to data.  The Web is not a bad place to start (having a better background education, including a little college math, maybe some statistics, is also recommended).


Finally, do you realize that you do not "write an equation of fifth order"?  Here's a hint -- to fit a fifth order polynomial, be sure to wire the number "5" to the connector marked "Polynomial Order" and supply at least 6 data points.


Bob Schor

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Message 2 of 4

Ok sorry for mistakes but i'm a beginner here in Labview and even in the forum so i would try to improve my knowledge to get better answers. Thank you for the time

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The best (and maybe the only way) to get "better in LabVIEW" is to write LabVIEW code and get it reviewed and critiqued by someone who can make intelligent suggestions (like "why does it take 20 screens to see everything?  Can't you make it fit onto a single screen?  Why are there so many wires running around?  Can't you simplify it, make it heirarchical so that I can, as they say, see the Forest for the Trees?") and help you to improve your code (hint -- anything other than trivial code probably should include a lot of user-written sub-VIs).


One way to learn what LabVIEW functions do and how to use them is to use the built-in LabVIEW Help system, including right-clicking a function and choosing Help from the drop-down menu.  Also look at the LabVIEW Examples (some of which are better than others).


As for learning Forum behavior, read a few posts (you'll see people, like me, requesting that users post code, not pictures) and the Welcome and Announcements section of the LabVIEW Community page, which has some useful Guidelines and Suggestions.


Bob Schor

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