System Identification Toolbox™ software supports estimation of linear models from both time- and frequency-domain data. For nonlinear models, this toolbox supports only time-domain data. For more information, see Supported Models for Time- and Frequency-Domain Data.
The data can have single or multiple inputs and outputs, and can be either real or complex.
Your time-domain data should be sampled at discrete and uniformly spaced time instants to obtain an input sequence
and a corresponding output sequence
u(t) and y(t) are the values of the input and output signals at time t, respectively.
This toolbox supports modeling both single- or multiple-channel input-output data or time-series data.
|Time-domain I/O data||One or more input variables u(t) and one or more output variables y(t), sampled as a function of time. Time-domain data can be either real or complex|
|Time-series data||Contains one or more outputs y(t) and no measured input. Can be time-domain or frequency-domain data.|
|Frequency-domain data||Fourier transform of the input and output time-domain signals. The data is the set of input and output signals in frequency domain; the frequency grid need not be uniform.|
|Frequency-response data||Complex frequency-response values for a linear system characterized by its transfer function G, measurable directly using a spectrum analyzer. Also called frequency function data. Represented by frd or idfrd objects. The data sample time may be zero or nonzero. The frequency vector need not be uniformly spaced.|
Note: If your data is complex valued, see Manipulating Complex-Valued Data for information about supported operations for complex data.