User`s guide

Concatenating Model Objects

When the Spect ralD ata property of individual idfrd objectsisnotempty,

horizontal and vertical concatenation handle

SpectralData,asfollows.

In case of horizontal concatenation, thereisnomeaningfulwaytocombinethe

SpectralData of individual idfrd objects, and the resulting Spe ctralData

property is empty. An empty property results because each idfrd object has

its own set of noise channels, where the number of noise channels equals the

number of outputs. When the resulting

idfrd object contains the same output

channels as each of the individual

idfrd objects, it cannot accommodate the

noise data from all the

idfrd objects.

In case of vertical concatenation, this toolbox concatenates individual noise

models diagonally. The following shows that

m.SpectrumData is a block

diagonal matrix of the power spectra and cross spectra of the output noise in

the system:

mN s

⎛

⎝

⎜

⎞

⎠

⎟



s in m.s is the abbreviation for the S pectrumData property name.