5 Dimensional Interpolation with Excel Data

Hi There,

I am trying to do a 5D interpolation with excel data (seen attached as an XLS file). The 5 Variables are: Temperature, Altitude, PLA, Speed and Fuel Flow. What I am trying to do is be able to put in 3 or 4 of the 5 vairables and then be able to obtian the unknowns. the reason interpolation is required is that I may be searching for vairable that are inbetween the data given.

For example:

lets say T = temperature, A = Altitude, P = PLA, S = Speed and FF = Fuel Flow. and we say T = 22 A = 5000 P = 74 S = 159 FF = ??

How can FF be found?

Any guidance would muchly be appreciated, I have been stuck on this for a while now.

[John D'Errico]

You want to supply 3 OR 4 of the variables? Not possible to do if it can be only 3 out of 5. That leaves 2 unknowns.

You want to pick ANY subset of those 5 variables, supply some values for the variables chosen, and predict the remaining variable(s)? Again, it is very possible that no solution exists, or that no unique solution exists. Much of the time, no solution will exist at all. Even if you were to pick 4 of the 5 variables, expect difficulties with this data.

Next, your data fills the space it inhabits very poorly. Might I stretch that to say obscenely poorly? Of course, that is terribly difficult to show in 5 dimensions, but this is why a large fraction of the time no interpolant will exist.

Would I touch this project (especially given this data) with a 10 foot pole? I'm sorry, but no way. You could not pay me to do so. Well, I can usually be bought, but my fees would be incredibly high here, and I would not promise any remote chance of success. :) (That is a combination of terribly crappy data & poorly specified goals will insure failure.) So I wish you luck, as you will need it.