Hi, I have 10 values for X, and other 10 values for Y, they are independent, But I have a function H(X,Y) that is dependent on these X, Y values. and I have 10 values for H too. What is the most direct way (preferably on excel ) that I can derive and equation H(X,Y) so that if I have any value of X, and any value of Y, I can get H(x,y)?? Thanks alot! if not on excel how can i do it on matlab?
2006-12-29 08:53:34 · 3 answers · asked by Arabi A 1 in Science & Mathematics ➔ Engineering
Hi,
I don't think it is possible to find an equation because X and Y are independent (but am not sure). First I would make a 3D plot in matlab of the points: H(X,Y) to get an idea of what type of equation you may be looking for. Than try to do some matlab surface fitting.
Good luck!
2006-12-29 09:27:45 · answer #1 · answered by Robert 2 · 0⤊ 0⤋
Deriving the actual governing equation could be a tall order.
What you probably want to do is a multiple regression. It can be done with either matlab or Excel. In either case it is probably important to plot the surfaces of the data and your chosen curve fit. In excel, you may need to add a regression add-in (I believe this is under the tools menu).
Try to fit a curve to something like:
H=a+b*x+c*y+d*xy+e*x^2+f*y^2
Depending on what your data looks like, you may need to remove terms from the above and/or add terms such as g*log(y) or the like.
It may also be possible to interpolate...
2006-12-29 19:21:57 · answer #2 · answered by Ron E 5 · 0⤊ 0⤋
use a 10th order equation that defines a function that passes through each point. perhaps solved using a newtonian polynomial.
2006-12-30 01:30:03 · answer #3 · answered by Anonymous · 0⤊ 0⤋