Creating and Manipulating Models

Accessing Property Values Using get

You access the property values of an LTI model sys with get. The syntax is

PropertyValue = get(sys,PropertyName)

where the string PropertyName is either the full property name, or any abbreviation with enough characters to identify the property uniquely. For example, typing

h = tf(100,[1 5 100],'inputname','voltage',...
                        'outputn','current',...
                        'notes','A simple circuit')
get(h,'notes')

produces

ans = 

    'A simple circuit'

To display all of the properties of an LTI model sys (and their values), use the syntax get(sys). In this example,

get(h)

produces

    num = {[0 0 100]}
    den = {[1 5 100]}
    Variable = 's'
    Ts = 0
    InputDelay = 0
    OutputDelay = 0
    ioDelay = 0
    InputName = {'voltage'}
    OutputName = {'current'}
    InputGroup = {0x2 cell}
    OutputGroup = {0x2 cell}
    Notes = {'A simple circuit'}
    UserData = []

Notice that default (output) values have been assigned to any LTI properties in this list that you have not specified.

Finally, you can also access property values using direct structure-like referencing. This topic is explained in the next section.

Setting LTI Properties

Direct Property Referencing