get (Control Design and Simulation Module, MathScript Function)

Member of the info class.

Syntax

infoval = get(SysIn, infotype)

Description

Returns information about linear time-invariant (LTI) system model. You can return numerator and denominator coefficient values from transfer function models. You can return zero and pole locations, as well as a gain value, from zero-pole-gain models. You can return A, B, C, and D matrices from state-space models. You can return delay information and the sampling time from all model forms. You can return only one information type at a time.

Examples

Inputs

Name	Description
SysIn	Specifies an LTI model in transfer function, zero-pole-gain, or state-space form.
infotype	Specifies the type of information you want to return from the SysIn model. You can specify only one information type at a time. infotype is a string that can take the following values: 'num' Specifies that you want to return the numerator polynomial coefficients of the SysIn model. This option is valid only when the SysIn model is in transfer function form. 'den' Specifies that you want to return the denominator polynomial coefficients of the SysIn model. This option is valid only when the SysIn model is in transfer function form. 'z' Specifies that you want to return the locations of the zeros of the SysIn model. This option is valid only when the SysIn model is in zero-pole-gain form. 'p' Specifies that you want to return the locations of the poles of the SysIn model. This option is valid only when the SysIn model is in zero-pole-gain form. 'k' Specifies that you want to return the feedback gain the SysIn model. This option is valid only when the SysIn model is in zero-pole-gain form. 'a' Specifies that you want to return the state matrix of the SysIn model. This option is valid only when the SysIn model is in state-space form. 'b' Specifies that you want to return the input matrix of the SysIn model This option is valid only when the SysIn model is in state-space form. 'c' Specifies that you want to return the output matrix of the SysIn model. This option is valid only when the SysIn model is in state-space form. 'd' Specifies that you want to return the direct transmission matrix of the SysIn model. This option is valid only when the SysIn model is in state-space form. 'ts' Specifies that you want to return the sampling time of the SysIn model. 'inputdelay' Specifies that you want to return the input delay of the SysIn model. 'outputdelay' Specifies that you want to return the output delay of the SysIn model. 'iodelay' or 'transdelay' Specifies that you want to return the transport delay, or the delay between the inputs and outputs of the SysIn model.

Outputs

Name

Description

infoval

Returns the value of the information you want to return from the SysIn model. You can specify only one value. The data type of the infoval input depends on the value you specify for the infotype input. If infotype is 'num', 'den', 'b', 'c', or 'd', infoval is a real scalar or real vector, depending on the number of elements you specify. If infotype is 'z' or 'p', infoval is a complex vector. If infotype is 'a' or 'k', 'infoval' is a real scalar or real matrix, depending on the number of inputs, outputs, or states of the model. If infotype is 'ts', infoval is a real scalar. If infotype is 'inputdelay', infoval is a real vector whose i-th element corresponds to the delay of the i-th input to the SysIn model. If infotype is 'outputdelay', infoval is a real vector whose j-th element corresponds to the delay of the j-th output from the SysIn model. If infotype is 'iodelay' or 'transdelay', infoval is a real matrix whose ij-th element corresponds to the delay between the i-th input and the j-th output of the SysIn model.

Examples

SysIn = tf(1, [0.2, 4])
SysOut = set(SysIn, 'num', [.05, 3], 'inputdelay', 0.8, 'ts', 0.1)
num = get(SysOut, 'num')
SysIn = ss(1, 1, 1, 0, 0.1)
SysOut = set(SysIn, 'c', 5)
c = get(SysOut, 'c')

Related Topics

set
pade
hasdelay
delay2z