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graph sampling and getting data from the graph for another vi....

Hi,

 

I have a text file which has irradiance value over a day.These values are at certain instant of time . I created a graph from these values that look like an inverted hyperbola.I am attaching the text and vi.If you load the text file and enter following data u will get a graph like i got.

 

; seperator

 

30 start

40 number of elements

 

Now what I want to do is to obtain data from the graph at an interval of ten minutes for 24 hrs and use it in an another vi.

 

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This could be a solution but I'm not sure if an 11th order polynomial is the right way to go 😞

You said irradiance, I think sun 🙂

So maybe by skipping the data before 05:00 and after 11:00 you can use a Gaussian fit.

Can't you sample data faster than every hour?

 

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i know and thanks for your reply but that was not the answer to my question.
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You asked for an interpolation, right?

That vi interpolates the values in array Xi using a polynomial function, returning values in array Yi.

If you enter in Xi all 10 minutes interval you get all you asked for 🙂

I modified it a bit using the data from the other thread so you can choose which one fits best your needs 🙂

Problem is that you have to choose the correct polynomial order.

 

This is a nice irradiation curve!

What will happen when some clouds passes over your pyranometer?

Your curve won't be so nice 😞

 

Hope this helped.

Regards

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