asp2osp

Convert an amplitude spectrum to an order spectrum.

Usage

asp2osp(a, df, f1 {, do, no, oini})

asp2osp(a, f, f1 {, do, no, oini})

a

amplitude or power spectrum (vector)

df

frequency resolution of the spectrum in Hz (scalar); 0 < df, f[i]=i*df

f

frequency scale of the spectrum in Hz (vector)

f1

frequency of the 1st order in Hz

do

resolution of the order spectrum; 0 < do (default=0.1)

no

length of the order spectrum; 2 < no (default=500)

oini

amplitude value for order spectrum initialization (default=0)

Description 1

The function implements a fast algorithm to convert a frequency spectrum a=f(f) into an order spectrum ao=f(f1,do). The algorithm uses interpolation (if a must be expanded) and maximum detection (if a must be compressed) to approximate the values of the order spectrum. The frequency range of the order spectrum is limited to 0 to f1*do*(no-1). All bins of o outside the frequency range of a (0..df*(nrow(a)-1) or f[0]..f[nrow(a)-1] are set the value oini.

Result

The order spectrum o (vector with no elements).

See also

ticks2f1, sig2osp, otrack1

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