MATLAB Function Reference

optimset

Create or edit an optimization options structure

Syntax

• options = optimset('param1',value1,'param2',value2,...)
  optimset
  options = optimset
  options = optimset(optimfun)
  options = optimset(oldopts,'param1',value1,...)
  options = optimset(oldopts,newopts)
  

Description

The function optimset creates an options structure that you can pass as an input argument to the following four MATLAB optimization functions:

• fminbnd
• fminsearch
• fzero
• lsqnonneg

You can use the options structure to change the default parameters for these functions.

Note    If you have purchased the Optimization Toolbox, you can also use optimset to create an expanded options structure containing additional options specifically designed for the functions provided in that toolbox. See the reference page for the enhanced optimset function in the Optimization Toolbox for more information about these additional options.

options = optimset('param1',value1,'param2',value2,...) creates an optimization options structure called options, in which the specified parameters (param) have specified values. Any unspecified parameters are set to [] (parameters with value [] indicate to use the default value for that parameter when options is passed to the optimization function). It is sufficient to type only enough leading characters to define the parameter name uniquely. Case is ignored for parameter names.

optimset with no input or output arguments displays a complete list of parameters with their valid values.

options = optimset (with no input arguments) creates an options structure options where all fields are set to [].

options = optimset(optimfun) creates an options structure options with all parameter names and default values relevant to the optimization function optimfun.

options = optimset(oldopts,'param1',value1,...) creates a copy of oldopts, modifying the specified parameters with the specified values.

options = optimset(oldopts,newopts) combines an existing options structure oldopts with a new options structure newopts. Any parameters in newopts with nonempty values overwrite the corresponding old parameters in oldopts.

Options

The following table lists the available options for the MATLAB optimization functions.

Option	Value	Description
Display	'off' | 'iter' | {'final'} | 'notify'	Level of display. 'off' displays no output; 'iter' displays output at each iteration; 'final' displays just the final output; 'notify' displays output only if the function does not converge.
FunValCheck	{'off'} | 'on'	Check whether objective function values are valid. 'on' displays a warning when the objective function returns a value that is complex or NaN. 'off' displays no warning.
MaxFunEvals	positive integer	Maximum number of function evaluations allowed.
MaxIter	positive integer	Maximum number of iterations allowed.
OutputFcn	function | {[]}	User-defined function that an optimization function calls at each iteration.
TolFun	positive scalar	Termination tolerance on the function value.
TolX	positive scalar	Termination tolerance on .

Examples

This statement creates an optimization options structure called options in which the Display parameter is set to 'iter' and the TolFun parameter is set to 1e-8.

• options = optimset('Display','iter','TolFun',1e-8)
  

This statement makes a copy of the options structure called options, changing the value of the TolX parameter and storing new values in optnew.

• optnew = optimset(options,'TolX',1e-4);
  

This statement returns an optimization options structure that contains all the parameter names and default values relevant to the function fminbnd.

• optimset('fminbnd')
  

See Also
optimset (Optimization Toolbox version), optimget, fminbnd, fminsearch, fzero, lsqnonneg

optimget

or

© 1994-2005 The MathWorks, Inc.