Re: 3D Data approximation
- To: mathgroup at smc.vnet.net
- Subject: [mg41501] Re: 3D Data approximation
- From: "Kevin J. McCann" <kmccann at umbc.edu>
- Date: Fri, 23 May 2003 03:25:11 -0400 (EDT)
- Organization: University of Maryland, Baltimore County
- References: <baiabe$dhn$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Can you not just check the residuals for the FIT result and the book result to see which gives a better (smaller) residual? I am making the assumption that you are interested in the minimization of the least-squares error. Kevin -- Kevin J. McCann Joint Center for Earth Systems Technology (JCET) Department of Physics UMBC Baltimore MD 21250 "Martin Wieloch" <marwiel at lycos.com> wrote in message news:baiabe$dhn$1 at smc.vnet.net... > Dear All > > Please help me if you can in solving my problem with data > approximation. > It is probably simple but I have had Mathematica just for one week. > I have got a set of experimental results {x,y,z} and I am trying > to approximate (the least square method) them with a function of > the form: a +a1x+a2x2+a3x3+a4x4+b1y+b2y2+b3y3+b4y4+cxy+c1x2y2 > > Is there is any better function than FIT. I used the fit function > to solve an example, but my results are slightly different from > those I found in a book-I have obtained higher coefficients a, b, c. > > I will be very much grateful if someone can help me. > > Regards, > Martin > >