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rms

Purpose

Computes the RMS response of the given frequency response function xf or auto-spectra a to a unity white noise input over the frequency range w.

Syntax

rm = feval(id_rc('@rms'),t,w)
rm = feval(id_rc('@rms'),a,w,1)

Description

The presence of a third input argument indicates that an auto-spectrum a is used (instead of frequency response function xf).

A trapezoidal integration is used to estimate the root mean squared response

  rms  =
 
1
ω2


ω1
 | t(ω) |2 dω
 =
 
1
ω2


ω1
 a(ω) dω

If xf is a matrix containing several column FRF, the output is a row with the RMS response for each column.

Warning

If only positive frequencies are used in w, the results are multiplied by 2 to account for negative frequencies.

See also

ii_cost


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