getData

Get current values of tunable-surface coefficients

Syntax

Kco = getData(K)

KcoJ = getData(K,J)

Description

Kco = getData(K) extracts the current value of a tunable surface. K is a tunableSurface object that represents the parametric gain surface:

$$K\left(n\left(\sigma \right)\right)=\gamma \left[K_0+K_1{F}_1\left(n\left(\sigma \right)\right)+\dots +K_M{F}_M\left(n\left(\sigma \right)\right)\right],$$

where:

• σ is a vector of scheduling variables.

• n(σ) is a normalization function (see the Normalization property of tunableSurface).

• γ is a scaling factor (see the Normalization property of tunableSurface).

• F₁,...,F_M are basis functions.

• K₀,...,K_M are tunable coefficients.

getData evaluates K at the current values of the coefficients K₀,...,K_M.

KcoJ = getData(K,J) extracts the current value of the coefficient of the Jth basis function F_J. Use J = 0 to get the constant coefficient K₀.

Input Arguments

K — Gain surface

tunableSurface object

Gain surface, specified as a tunableSurface object,

J — Index of basis function

nonnegative integer

Index of basis function, specified as a nonnegative integer. To extract the constant coefficient K₀, use J = 0.

Output Arguments

Kco — Current coefficient values

array

Current coefficient values of the tunable surface, returned as an array.

If the tunable surface K is a scalar-valued gain, then the length of K is (M+1), where M is the number of basis functions in the parameterization. For example, if K represents the tunable gain surface:

$$K\left(\alpha ,V\right)=K_0+K_1\alpha +K_{2}V+K_3\alpha V,$$

then Kco is the 1-by-4 vector [K₀,K₁,K₂,K₃].

For array-valued gains, each coefficient expands to the I/O dimensions of the gain. These expanded coefficients are concatenated horizontally in Kco. (See tunableSurface.) For example, for a two-input, two-output gain surface, Kco has dimensions [2,2(M+1)].

KcoJ — Coefficient of Jth basis function

scalar | array

Coefficient of the Jth basis function in the tunable surface parameterization, returned as a scalar or an array.

If the tunable surface K is a scalar-valued gain, then KcoJ is a scalar. If K is an array-valued gain, then KcoJ is an array that matches the I/O dimensions of the gain.

Version History

Introduced in R2015b