surface fitting question
- To: mathgroup at smc.vnet.net
- Subject: [mg61328] surface fitting question
- From: Ralph Smith <ralph at lkjlkj.com>
- Date: Fri, 14 Oct 2005 22:23:55 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
I have this data in a file. It is a 2D table that 26 rows and 17 columns.
|
-----------------------------------------------------------------------
| 0.000 0.000 0.000 ... 0.000 0.000 0.000
| 0.050 0.050 0.155 ... 16.409 19.375 20.156
| .
| .
| .
| 47.500 50.000 55.000 ... 2017.500 2075.580 2182.765
-----------------------------------------------------------------------
|
I would like to find an equation that describes this surface using
mathematica. I think that 3rd degree polynomials would be what I'm looking
for. So, maybe
data[x,y] = ax^3 + bx^2 + cx + d + ey^3 + fy^2 + gy
I've seen and example that uses Fit[], so I think this can be done, but I'm
a novice at mathematica and don't know how to set this problem up. I have been
able to fit a polynomial to curve data, but now I need to fit a surface.
thanks,
Ralph