topic Re: Labview in LabVIEW

Labview

Whifitws — Wed, 11 Mar 2020 16:05:47 GMT

Knowing the coordinates of the experimental points affected by measurement errors, the coefficients
ac and bc of the regression line are determined using the Linear Fit.vi function in the menu
Mathematics / Fitting.
In addition to the values of the two coefficients, the Linear Fit.vi function generates at the Best Linear output
Fit the values of the Y '' coordinates of the points on the regression line and having the same
X coordinates as the experimental points.
The string of numeric values Y '' is the one used for plotting the third graph.

How can i do that? Thank you!

Re: Labview

aeastet — Wed, 11 Mar 2020 16:23:55 GMT

You mean something like this?

Re: Labview

Whifitws — Wed, 11 Mar 2020 16:58:48 GMT

I mean, yeah, something like that, but now i can't find the calculated a and b and the regression line does not appear on the graph.

Re: Labview

Whifitws — Wed, 11 Mar 2020 17:37:14 GMT

Thank you for your time, I solved the problem.

Re: Labview

altenbach — Thu, 12 Mar 2020 07:56:23 GMT

Maybe something like this instead?

Re: Labview

johntrich1971 — Thu, 12 Mar 2020 12:40:53 GMT

@Whifitws wrote:

Thank you for your time, I solved the problem.

When you have solved a problem it is polite to share your solution for the benefit of others who may have the same problem in the future.

Re: Labview

altenbach — Thu, 12 Mar 2020 15:15:41 GMT

@Whifitws wrote:

The string of numeric values Y '' is the one used for plotting the third graph.

How can i do that? Thank you!

There are no "strings" anywhere. Your descriptions makes about as much sense as your code. I took the liberty to do some alternative interpretations. 😉

@aeastet wrote:

You mean something like this?

This also makes no sense at all. Your linear fit is done on two y-values and ten x-values. The inputs need to have the same size.

@Whifitws wrote:

Thank you for your time, I solved the problem.

Are you sure? Please let us give a chance to check it. Also, next time please use a more useful subject line. Since this is the LabVIEW forum, every single discussion is about LabVIEW, no need to repeat that in the title. Something like "Simulation of a linear fit" would have been more useful.

Re: Labview

Whifitws — Thu, 12 Mar 2020 16:54:26 GMT

Yes, this is the final result.

Re: Labview

altenbach — Thu, 12 Mar 2020 17:20:31 GMT

No, that's not a "result", just an oversized photograph of a monitor showing some LabVIEW code. Attach the VI instead.

Re: Labview

Whifitws — Thu, 12 Mar 2020 18:19:40 GMT

I apologise for the misunderstanding.

Re: Labview

altenbach — Thu, 12 Mar 2020 21:09:35 GMT

You swapped the definition of "ideal" (contains noise) and experiemental" (contains no noise).
Equal distributed noise is not realistic. Noise is typically Gaussian.
Your scaling the error with Y. Is that really realistic? (i.e. no error if y=0)
Even if you really want an even noise distribution, your code is pure Rube Goldberg.
Please don't maximize the front panel to the screen. That's extremely annoying!
Did you even look at my example code? Did you understand it?
...

Re: Labview

altenbach — Thu, 12 Mar 2020 21:14:44 GMT

@altenbach wrote:

Equal distributed noise is not realistic.

Your scaling the error with Y. Is that really realistic? (i.e. no error if y=0)

Here are some alternative code version that duplicate your weird nose generation.

Re: Labview

Whifitws — Sun, 15 Mar 2020 12:46:46 GMT

This is how we learnt în university, we haven't learned the more complex functions yet.