Complex interpolation

[Orlando]

Dear all,

I turn to you in the hopes of someone helping me out with this complex interpolation problem.

Basically I have a set of data in the excel file attached, that basically has two parameters ZZ1 and ZZ2 that need to be calculated based on an interpolation of FOUR other parameters to the left.

I really don't know how to solve this, I would really appreciate it if someone could help me out.

Thank you so much!

Best regards,


ORLANDO

 

[eibi]

Orlando - welcome to the forums!

Can you provide the desired outcome for the example you provided so we can test that the formulas we compose actually achieve the output you want?

I've got an example for you (attached) - but I've just guessed about how you want to apply the parameters you've set... In any case, the SUMPRODUCT() formula is the place I would start.

Isaac

 

[jeffreyweir]

Sounds to me like you need to do a regression analysis on this.

I've previously done two-way interpolation, as a formula challenge. Very complicated. See http://forum.chandoo.org/threads/formula-challenge-010-two-way-interpolation.11305/

 

[NARAYANK991]

Hi ,

I am not so sure it is so straightforward ; if H , A , k1 and k2 are the independent variables , and ZZ1 and ZZ2 are the dependent variables , then we need to have enough cases , where only one variable is changed at a time , so that an idea of how the dependent variables are related to the variable which is changing can be seen.

In your case , if we look at row 6 , it has two variables which have changed from row 5. A similar problem exists for the next set. We can form an idea of how ZZ1 and ZZ2 vary when H and k2 change individually , but it is not so easy to identify how they change when A or k1 changes individually.

If there are only two end points for which data is available for all 4 variables , then we can assume any kind of curve between these two end points ; can we assume a straight line ?

Lastly , is this the only case where this is going to be applied , or will there be many such data sets ? If yes , then how will they be structured ? If you can upload a data set which is your real life working data , it may be easier to look at an appropriate solution.

Narayan

 

[eibi]

In any case, the SUMPRODUCT() formula is the place I would start.

I'm embarrassed. I can't be very helpful on this thread...Please excuse my initial irrelevant reply.