wcgainOptions

Option set for wcgain, wcgainplot, wcnorm, or wcsens

Syntax

opt = wcgainOptions
opt = wcgainOptions(Name,Value,...)

Description

opt = wcgainOptions returns the default option set for a wcgain calculation. The commands wcgainplot, wcnorm, and wcsens also use wcgain to compute their results. Use a wcgainOptions options set to control options for those calculations.

opt = wcgainOptions(Name,Value,...) creates an option set with the options specified by one or more Name,Value pair arguments.

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.

'Sensitivity'

Determines whether to compute the sensitivity of worst-case gain with respect to each individual uncertain element.

Sensitivity is a string that takes the following values:

  • 'on'wcgain computes the sensitivity of the worst-case gain with respect to each individual uncertain element. This provides an indication of which elements are most problematic.

  • 'off'wcgain does not compute the sensitivity of the worst-case gain with respect to each individual uncertain element.

Default: 'on'

'VaryUncertainty'

Percentage variation of uncertainty for sensitivity calculations. The sensitivity estimate uses a finite difference calculation.

Default: 25

'LowerBoundOnly'

Determines whether only the lower bound is computed.

LowerBoundOnly is a string that takes the following values:

  • 'on'wcgain only computes a lower bound on the worst-case gain

  • 'off'wcgain computes lower and upper bounds on the worst-case gain

Default: 'off'

'MaxOverFrequency'

MaxOverFrequency is a string that takes the following values:

  • 'on'wcgain computes the worst-case H norm (peak gain over frequency)

  • 'off'wcgain computes the worst-case gain at each frequency point

Default: 'on'

'MaxOverArray'

For uncertain model arrays, determines if worst-case gain is calculated over entire array or individually for all models in array.

MaxOverArray is a string that takes the following values:

  • 'on'wcgain computes the worst-case gain over all models

  • 'off'wcgain computes the worst-case gain for each model individually

Default: 'on'

'AbsTol'

Absolute tolerance on computed bound.

The algorithm terminates if UpperBound-LowerBound <= max(AbsTol, Reltol*UpperBound).

Relaxing tolerance speeds up the computation.

Default: 0.02

'RelTol'

Relative tolerance on computed bound.

The algorithm terminates if UpperBound-LowerBound <= max(AbsTol, Reltol*UpperBound).

Default: 0.05

'AbsMax'

Absolute threshold for lower bound.

The algorithm terminates if LowerBound >= AbsMax + RelMax * NominalGain.

Specify AbsMax and RelMax to terminate when the lower bound is large enough compared to the nominal gain.

Default: 5

'RelMax'

Relative threshold for lower bound.

The algorithm terminates if LowerBound >= AbsMax + RelMax * NominalGain.

Specify AbsMax and RelMax to terminate when the lower bound is large enough compared to the nominal gain.

Default: 20

'NSearch'

Number of lower bound searches at each frequency

Default: 2

Output Arguments

opt

Option set containing the specified options for wcgain.

Examples

Create an options set for wcgain with only the lower bound being calculated and 5 lower bound searches at each frequency.

opt = wcgainOptions('LowerBoundOnly','on','Nsearch',5)

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

opt = wcgainOptions;
opt.LowerBound = 'on';
opt.NSearch = 5;
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