"Interpolation"

[YornEngtang]

Dear all friend, how to interpolation as equation in highlight?
my row of ( fi,Nc ,Nq,Naq ) start from 0 to 50 or more than.
Please help explain us. thank you all in advance.

[LucMeekes · Accepted solution]

Please attach your worksheet. It's very hard to debug a picture.

What is the error message regarding fi?

There should be no problem for your vectors fi and Nc being large, as shown here:

Success!
Luc

[YornEngtang]

I'm Engtang. thank you prof.  LucMeekes.

[Werner_E]

.) Phi' seems to be in ascending order as its needed for "linterp" - hopefully this is also true for the values you don't show in the picture!?

EDIT: As Freds answer shows it looks like I need new specs - I didn't notice the two equal values (16) which also are visible in the picture!

.) Did you ensure that Phi' and Nc are of same length and that both contain real values only - no text and no complex numbers?

.) Another idea would be to check if the labels of all Phi' are the same - especially if the error message is telling you something about an unknown variable.

Otherwise, as Luc already wrote, you would have to attach your worksheet which would have been a good idea in the first place anyway.

[YornEngtang]

Thank you prof. Werner_E 😍

[Fred_Kohlhepp]

Hmmm

[Werner_E]

Well spotted, Fred!

The typo (as I guess) is also seen in the picture provided in the initial post, but I didn't notice it 😞

Changing the first 16 to 15 of course cures the problem:

[YornEngtang]

Hi prof. FredKohlhepp

your highlight in picture is noticed. 

Thank you for solve this this problem.