How can I obtain the parameters estimated in every iteration of lsqcurvefit?

x = lsqcurvefit(fun,x0,xdata,ydata)

Lsqcurvefit starts at x0 (initial guess) and finds coefficients x to best fit the nonlinear function fun(x,xdata) to the data ydata (in the least-squares sense). Then, it returns the final value(s) of x0 after all iterations are completed. Is it possible to get all the different values, from all iterations, of the initial guess until the solution is found?

Thanks in advance!

Answer 1

[the cyclist]

Did you try carefully reading the documentation for lsqcurvefit?

In the Input Arguments section, under options, the documentation explains how to display iteration-level details. That seems promising.

[nt_ba]

Thanks for your reply, but i want an iterative display of the values of x0. I don't think that's what is being explained in the Input Arguments section.

[the cyclist]

Hm. x0 is an input, so I am not sure what you are asking for. (Granted, I don't have experience using this particular function.)

If there are no output options that suit your needs, you could always copy the function to your own version (e.g. mylsqcurvefit), and edit it so that it outputs the things you need while it is executing.

Answer 2

[Alan Weiss]

Perhaps you could use an output function to give you the information you want.

Alan Weiss

MATLAB mathematical toolbox documentation