Creating and Manipulating Models | ![]() ![]() |
Referencing FRD Models Through Frequencies
You can extract subsystems from FRD models, as you do with other LTI model types, by indexing into input and output (I/O) dimensions. You can also extract subsystems by indexing into the frequencies of an FRD model.
To index into the frequencies of an FRD model, use the string 'Frequency'
(or any abbreviation, such as, 'freq'
, as long as it does not conflict with existing I/O channel or group names) as a keyword. There are two ways you can specify FRD models using frequencies:
For example, if sys
is an FRD model with five frequencies, (e.g., sys.Frequency=[1 1.1 1.2 1.3 1.4]
), then you can create a new FRD model sys2
by indexing into the frequencies of sys
as follows.
displays the second and third entries in the frequency vector.
Similarly, you can use logical indexing into the frequencies.
You can also combine model extraction through frequencies with indexing into the I/O dimensions. For example, if sys
is an FRD model with two inputs, two outputs, and frequency vector [2.1 4.2 5.3]
, with sys.Units
specified in rad/s, then
specifies sys2
as a SISO FRD model, with one frequency data point, 2.1 rad/s.
![]() | Extracting and Modifying Subsystems | Referencing Channels by Name | ![]() |