Transform Data
System Identification Toolbox™ provides tools for analyzing data and for estimating and evaluating models in both the time and the frequency domains. To use tools and methods that are not in the same domain as your measured data, you can transform your data between the time domain and the frequency domain.
The iddata object stores time-domain
or frequency-domain data.
Time-domain data consists of one or more input variables u(t) and one or more output variables y(t), sampled as a function of time.
Frequency-domain data consists of either transformed input and output time-domain signals or system frequency response sampled as a function of the independent variable frequency.
For detailed information about representing time-domain and frequency-domain data in MATLAB®, see Representing Data in MATLAB Workspace.
Functions
fft | Fast Fourier transform (FFT) of iddata object |
ifft | Transform iddata objects from frequency to time domain |
etfe | Estimate empirical transfer functions and periodograms |
spa | Estimate frequency response with fixed frequency resolution using spectral analysis |
spafdr | Estimate frequency response and spectrum using spectral analysis with frequency-dependent resolution |
Topics
Data Transformation Using the App
- Transform Time-Domain Data in the App
Transform time-domain data to frequency-domain or frequency-response data. - Transform Frequency-Domain Data in the App
Transform frequency-domain input-output data to time-domain or frequency-response data. - Transform Frequency-Response Data in the App
Transform frequency-response data to frequency-domain input-output data or to frequency-response data with a different frequency resolution.
Data Transformation Using the Command Line
- Supported Data Transformations
Transform between time-domain and frequency-domain data at the command line. - Transform Between Time-Domain and Frequency-Domain Data
Transform between time-domain and frequency-domainiddataobjects at the command line. - Transforming Between Frequency-Domain and Frequency-Response Data
Transform betweeniddataandidfrdobjects at the command line.
