Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

Thread Subject:
differences in Lsqncurvefit between 2008a and 2008b

Subject: differences in Lsqncurvefit between 2008a and 2008b

From: Hugh

Date: 17 Dec, 2009 16:04:23

Message: 1 of 2

Hi there,

Using exactly the same code and exactly the same data I am getting different results when using lsqncurvefit with 2008a and 2008b?

What are the major differences between the two versions. Neither converge completely but am I to assume 2008b is more accurate?

Hugh

Subject: differences in Lsqncurvefit between 2008a and 2008b

From: Alan Weiss

Date: 21 Dec, 2009 13:36:16

Message: 2 of 2

Hugh wrote:
> Hi there,
>
> Using exactly the same code and exactly the same data I am getting
> different results when using lsqncurvefit with 2008a and 2008b?
>
> What are the major differences between the two versions. Neither
> converge completely but am I to assume 2008b is more accurate?
>
> Hugh
 From the R2008b release notes:

fsolve, lsqcurvefit, lsqnonlin Algorithm and Options Changes

The Levenberg-Marquardt algorithm was refactored in the solvers fsolve,
lsqcurvefit and lsqnonlin. It is now a more standard implementation,
that accepts and preserves sparse Jacobians.

Choose between the algorithms used in fsolve, lsqcurvefit and lsqnonlin
using the new Algorithm option.

There is a new ScaleProblem option that can sometimes help the
Levenberg-Marquardt algorithm converge.

Alan Weiss
MATLAB mathematical toolbox documentation

Tags for this Thread

What are tags?

A tag is like a keyword or category label associated with each thread. Tags make it easier for you to find threads of interest.

Anyone can tag a thread. Tags are public and visible to everyone.

Contact us