Problems with MLE method and curve fitting!

Hi everyone, I hope someone can help me!

How can I estimate the parameters of a function (using an anonymous function) with the maximum likelihood method? I've seen several things on the internet (like mle, fminsearch) but nobody gives me the parameter values!

Example I have:

eq = fittype (@ (a, b, c, x) a * x. ^ 2 + b * x + c);

how do i get the values ​​of a, b and c with the MLE method?

Thanks a lot to everyone!

Answer 1

[Rishabh Mishra]

Hi,

Based on my understanding, you can use 'polyfitn' function to estimate the parameters a, b, c. For this purpose, you require a set of values of 'x' as double array and the corresponding values of function (a*x.^2 + b*x + c) stored in another double array say 'y'. Use the code below to estimate the co-efficient values for the function (a*x.^2 + b*x + c).

% assuming 'x' & 'y' are double arrays
% 'y' stores the function value corresponding to each element of 'x'
% 'n' stores degree of the function
n = 2;
p = polyfitn(x,y,n);

The values p.Coefficients(1), p.Coefficients(2) & p.Coefficients(3) correspond to estimated values of coefficients a, b & c respectively.

Hope this helps.