pydsm.delsig.rmsGain

pydsm.delsig.rmsGain(H, f1, f2, N=100)

Compute the root-mean-square gain of a DT transfer function.

The computation is practiced on an assigned frequency interval. By root-mean-square, it is meant that the magnitude response of the transfer function is squared and averaged over the band of interest. Then, the square root of this averaged value is returned.

Parameters

Htuple

transfer function either in (z,p,k) or (n,d) form

f1real

lower bound of frequency band on which the transfer function is evaluated

f2real

upper bound of frequency band on which the transfer function is evaluated

Nint, optional

number of points where the transfer function is evaluated in the interval. Defaults to 100.

Returns

rmsreal

rms value of the discrete time transfer function.

Notes

The discrete-time transer function H is evaluated in the frequency band (f1,f2). Spanning of the bandwidth is linear. Frequencies are normalized in the [0, 0.5] interval.

Warning: the result of the computation is normalized in the number of points used for the computation, but not on the frequency range.

This computation could be practiced much more accurately and possibly faster, using algorithms for the numerical computation of integrals.

Examples

>>> import numpy as np
>>> v = np.sin(np.linspace(0, 20*np.pi, 1024))
>>> pydsm.delsig.rms(v)
0.70676142986866519