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Modal parameters from frequency-response functions

estimates the natural frequencies of `fn`

= modalfit(`frf`

,`f`

,`fs`

,`mnum`

)`mnum`

modes of a system with
measured frequency-response functions `frf`

defined at frequencies
`f`

and for a sample rate `fs`

. Use
`modalfrf`

to generate a matrix of
frequency-response functions from measured data. `frf`

is assumed
to be in dynamic flexibility (receptance) format.

`[___] = modalfit(`

estimates the modal parameters of the identified model `sys`

,`f`

,`mnum`

,`Name,Value`

)`sys`

. Use
estimation commands like `ssest`

(System Identification Toolbox) or `tfest`

(System Identification Toolbox) to create `sys`

starting from a measured
frequency-response function or from time-domain input and output signals. This syntax
allows use of the `'DriveIndex'`

,
`'FreqRange'`

, and `'PhysFreq'`

name-value
arguments. It typically requires less data than syntaxes that use nonparametric
methods. You must have a System Identification Toolbox™ license to use this syntax.

[1] Allemang, Randall J., and David L. Brown. “Experimental Modal Analysis and Dynamic Component Synthesis, Vol. III: Modal Parameter Estimation.” Technical Report AFWAL-TR-87-3069. Air Force Wright Aeronautical Laboratories, Wright-Patterson Air Force Base, OH, December 1987.

[2] Brandt, Anders. *Noise and Vibration Analysis:
Signal Analysis and Experimental Procedures*. Chichester,
UK: John Wiley & Sons, 2011.

[3] Ozdemir, Ahmet Arda, and Suat
Gumussoy. "Transfer Function Estimation in System Identification Toolbox via Vector Fitting." *Proceedings of the 20th World Congress of the
International Federation of Automatic Control*, Toulouse, France, July
2017.

`modalfrf`

| `modalsd`

| `n4sid`

(System Identification Toolbox) | `tfest`

(System Identification Toolbox) | `tfestimate`

- Modal Analysis of Identified Models
- System Identification Overview (System Identification Toolbox)
- System Identification Workflow (System Identification Toolbox)
- Supported Continuous- and Discrete-Time Models (System Identification Toolbox)