**Re: FindFit and NormFunction (to find a best fit by medians)**On 9/6/08 at 2:05 AM, nycstern@gmail.com (Stern) wrote:
>I'm trying to use FindFit to find a best linear fit using Medians
>rather than Mean
>At one time, I believe the following code worked (I used it in
>several places, and never noted it failing, but it hasn't been used
>in a while and I don't actually remember):
>FindFit[sampledata,a+b*x,{a,b},x,NormFunction->(Sqrt[Median[#^2]]&)]
It is unclear to me what you mean by fitting using means or
medians. I am going to assume you mean by using means you mean
using FindFit with the default norm...

**Find best fit of number**Hello,
can someone help me with this problem:
I have a numeric-double-control as input.
Then i have a numeric-double-array-constant with ~10 numbers.
The output should be one of the constant-numbers which is the nearest to the input-number.
For example:
input: 2.7
constant-array: 0.1 / 0.7 /2.1 / 3 / 5.5 / 9
The the ouput should be: 3
Thanks for your help
Hello Aitortxo,
I already did it like you said but i thought there woul be an easier/faster way to do it than searching an array.
findbestfit.vi:
http://forums.ni.com/attachments/ni/170/153509/1/findbestfit.vi
What about this one?
...

**Finding best fit for surf**Hi,
I am trying to formulate an equation based on some measured data. There are two variables, lets call them x and y and a resulting value z. I have test data for an array of points from which I have compiled a 2-d array using interp2. I can plot this using surf but the "basic fitting" is not available. I would like to have an equation z=f(x,y) for the data. Does anyone know how I can produce this equation in Matlab?
Much appreciated
Tim
...

**Finding Best fit coefficients**Lets say Y = F(x) where F = (A/(B-Cx)^2 ) -D and A,B,C,D are all constants.
I have a column of data for Y, and a column of data for x and all I know is that A<D.
What do I do to find the coefficients A,B,C,D such that the function F has the best fit with the data?
Thanks,
Arvindh
"Arvindh " <arvindh.rao@gmail.com> wrote in message <hrqise$ht7$1@fred.mathworks.com>...
> Lets say Y = F(x) where F = (A/(B-Cx)^2 ) -D and A,B,C,D are all constants.
>
> I have a column of data for Y, and a column of data for x and all I know is that A<D.
&g...

**Find the function that best fits**Dear collages,
I have implemented a code to obtain information. Now I want to obtain a function that fits to this information. Is there any option to say to Mathematica to look for the best function that fit to dates? Thank you very much.
i think you need to be allot more specific about what you have and
what your looking for. stated well, and if a limited question, there
are many very capable math group participators i bet will help answer
there are many new date functions. fit date?
...

**Re: Find the function that best fits**On 4/20/13 at 5:45 AM, JFONFRIA@UJAEN.ES (JFONFRIA) wrote:
>I have implemented a code to obtain information. Now I want to
>obtain a function that fits to this information. Is there any option
>to say to Mathematica to look for the best function that fit to
>dates?
No. The problem you pose is ill defined and open ended. Key is
defining what is meant by "best". Mathematica provides a variety
of tools suitable for fitting functions to data. It is up to you
to use them appropriately. And only you can define
"appropriate", "best" etc for your ...

**best fit sphere and finding its center**hi,
i have (X,Y,Z) coordinates of a GPS receiver mounted on a telescope.which apparently forms half of a sphere.as GPS data are not 100% precise thus i cant get accurate surface of the half sphere. therefore i need to fit the points on the sphere. how do i get the best fit sphere and center of it.
regards
taaj
"syed " <taaj_1079@hotmail.com> wrote in message <i148fd$lqv$1@fred.mathworks.com>...
> hi,
> i have (X,Y,Z) coordinates of a GPS receiver mounted on a telescope.which apparently forms half of a sphere.as GPS data are not 100% precise thus i cant get ...

**How to find the best fit for a data with multivariables**Hi
I have a matrix of size 800 x 5 containing the data of the five independent variables a,b,c,d,e and vector 800 x 1 containing the data for the dependent variable z.
I want to fit a model for the data giving the functional relation between dependent variable z and five independent variables a,b,c,d,e.
My questions are:
1. Which functions/tools in MATLAB should I used to get the best fit?
2. Which MATLAB tools/functions should I used to get an expression of the fitted model and also validate the fitted model?
Best Regards,
Rabi
"Rabi " <rabikhattak@gmail.c...

**Find the best fit with an exponential curve (or spherical)**Hello,
Given vectors of data xdata and ydata, I want to find coefficients to find the best fit to some kind of exponential decay equation.
Please have a look at my data. I posted it as two vectors at the end of this message, which you can copy and paste into MATLAB. The ydata vs. xdata plot clearly shows a exponential decay.
I used the command lsqcurvefit with the function
F(p,xdata) = p(1)*exp(p(2)*(xdata+p(3)))
However it fails and I don't know what is wrong woth it. It might be the function or any settings. Its the first time that I use this kind of approach. I only u...