Documentation

findopOptions

Set options for finding operating points from specifications

Syntax

options = findopOptions
options = findopOptions(Name,Value)

Alternatives

As an alternative to findopOptions function, set options for finding operating points in the Linear Analysis Tool.

Description

options = findopOptions returns the default operating point search options.

options = findopOptions(Name,Value) returns an option set with additional options specified by one or more Name,Value pair arguments. Use this option set to specify options for the findop command.

Input Arguments

Name-Value Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside single quotes (' '). You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

findopOptions takes the following Name arguments:

'OptimizerType'

Optimizer type used by the optimization algorithm of findop, specified as one of the following strings:

  • 'graddescent_elim' — Enforces an equality constraint to force the time derivatives of states to be zero (dx/dt=0, x(k+1)=x(k)) and the output signals to be equal to their specified ‘Known' value. The optimizer fixes the states, x, and inputs, u, that are marked as ‘Known' in an operating point specification and then optimizes the remaining variables.

  • 'graddescent' — Enforces an equality constraint to force the time derivatives of states to be zero (dx/dt=0, x(k+1)=x(k)) and the output signals to be equal to their specified ‘Known' value. findop also minimizes the error between the states, x, and inputs, u, that are marked as ‘Known' in an operating point specification. If there are not any inputs or states marked as ‘Known', findop attempts to minimize the deviation between the initial guesses for x and u and their trimmed values.

  • 'lsqnonlin' — Fixes the states, x, and inputs, u, that are marked as 'Known' in an operating point specification and optimizes the remaining variables. The algorithm then tries to minimize both the error in the time derivatives of the states (dx/dt=0, x(k+1)=x(k)) and the error between the outputs and their specified 'Known' value.

  • 'simplex' — Uses the same cost function as lsqnonlin with the direct search optimization routine found in fminsearch.

For more information about these optimization algorithms, see fmincon and fminsearch in the Optimization Toolbox™ documentation.

Default: 'graddescent_elim'

'OptimizationOptions'

Options for the optimization algorithm, specified as a structure. Create the structure using the optimset command. For more information on these options, see the optimset reference page.

'DisplayReport'

Flag indicating whether to display the operating point summary report, specified as either 'off' or 'on'.

  • 'on' — Display the operating point summary report in the MATLAB® command window when running findop.

  • 'off' — Suppress display of the summary report.

Default: 'on'

Output Arguments

options

Option set containing the specified options for findop.

Examples

collapse all

Create Options Set for Operating Point Search

Create an options set for operating point search that sets the optimizer type to gradient descent and suppresses the display output of findop.

options = findopOptions('OptimizerType','graddescent',...
                        'Display','off');
                       

Alternatively, use dot notation to set the values of options.

options = findopOptions;
options.OptimizerType = 'graddescent';
options.Display = 'off';

See Also

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