Control System Toolbox™

get - Access LTI property values

Syntax

Value = get(sys,'PropertyName')
Struct = get(sys)

Description

Value = get(sys,'PropertyName') returns the current value of the property PropertyName of the LTI model sys. The string 'PropertyName' can be the full property name (for example, 'UserData') or any unambiguous case-insensitive abbreviation (for example, 'user'). You can specify any generic LTI property, or any property specific to the model sys (see LTI Properties for details on generic and model-specific LTI properties).

Struct = get(sys) converts the TF, SS, or ZPK object sys into a standard MATLAB^® structure with the property names as field names and the property values as field values.

Without left-side argument,

get(sys)

displays all properties of sys and their values.

Example

Consider the discrete-time SISO transfer function defined by

h = tf(1,[1 2],0.1,'inputname','voltage','user','hello')

You can display all LTI properties of h with

get(h)
           num: {[0 1]}     
           den: {[1 2]}     
       ioDelay: 0           
      Variable: 'z'         
            Ts: 0.1         
    InputDelay: 0           
   OutputDelay: 0           
     InputName: {'voltage'} 
    OutputName: {''}        
    InputGroup: [1x1 struct]
   OutputGroup: [1x1 struct]
          Name: ''          
         Notes: {}          
      UserData: 'hello' 

or query only about the numerator and sample time values by

get(h,'num')

ans = 
    [1x2 double]

and

get(h,'ts')

ans =
    0.1000

Because the numerator data (num property) is always stored as a cell array, the first command evaluates to a cell array containing the row vector [0 1].

Remark

An alternative to the syntax

Value = get(sys,'PropertyName')

is the structure-like referencing

Value = sys.PropertyName

For example,

sys.Ts
sys.a
sys.user

return the values of the sample time, matrix, and UserData property of the (state-space) model sys.

See Also

frdata, set, ssdata, tfdata, zpkdata

gensig

getdelaymodel