how to use linear fit

[Brein]

Anyone here to help me how to use the linear fir vi?

Is this vi capable of analyzing a line with a negative slope?

What shold i input in this vi? I tried connecting my x and y arrays in this vi but still outputs nothing. Is there a bug on this vi?

Is there a way to fit a line in my data points like what excel does?

Thanks again for helping me numerous times.

Brein

Stuck again

[altenbach]

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Brein wrote:

Is this vi capable of analyzing a line with a negative slope?

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Yes!

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Brein wrote:

Anyone here to help me how to use the linear fir vi?

...

What shold i input in this vi? I tried connecting my x and y arrays in this vi but still outputs nothing. Is there a bug on this vi?

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See the help page. There is not bug! Please show us your VI so we can see what you are doing wrong. (make sure to include some default data).

[Brein]

up this problem. Any suggestions on getting a linear fit like what excel does?

[altenbach]

LabVIEW can easily do linear fit. A linear fit is a rather trivial operation.

As said, show us your VI and we show you what you are doing wrong.

[Brein]

This is my vi. I am using labview 7.0 and vision 7.0. This project is about finding a relationship between concentration of a certain solution and its color value using rgb space. I am already able to plot the relation ship found in sequence structure 3 of 3(assuming the first sequence is 0 of 3). How to put a linear fit in my data points?

[Brein]

where are you?  still there?

[Brein]

If you think this is very trivial, then maybe you give me a sample program

[altenbach]

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Brein wrote:

where are you?  still there?

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Hey, I am on the west coast and is was way past midnight for me. Even I need some zzz's once in a while. 😄

[altenbach]

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Brein wrote:
This is my vi. I am using labview 7.0 and vision 7.0. This project is about finding a relationship between concentration of a certain solution and its color value using rgb space. I am already able to plot the relation ship found in sequence structure 3 of 3(assuming the first sequence is 0 of 3). How to put a linear fit in my data points?

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So you need to do a global fit to three datasets (R, G, & B). Since you seem to deal with a greyscale image, it is probably sufficient to fit only a single channel. What function do you use in excel?

Sorry, I don't have the vision module. Can you strip down your VI as follows:

• create indicators on the three orange arrays in frame #2. (right-click wires, create indicator)
• Run the VI so the indicators contain data.
• Turn the indicators into diagram constants (right-click..change to constants). Wires will be broken, leave them broken!
• Save the VI under a new name and attach it again.

I am quite busy today, maybe I can look at it tonight if nobody else gives a solution.

[Claire_Reid]

Please see the example VIs for the Linear Fit VI. If you go to the context help for Linear Fit.vi, you can see a bunch of examples for this VI.

Also, I ran your code and no data is graphed.