msspectrum
 Note that the msspectrum method is
only available for the periodogram and welch spectrum
estimation objects. The meansquared spectrum is intended
for discrete spectra (from periodic, discretetime signals). The distribution
of the mean square value across frequency is the msspectrum. Unlike
the power spectral density (see psd below), the
peaks in the meansquare spectrum reflect the power in the signal
at a given frequency. For the PSD, the power is reflected as the area
in a frequency band. The units of the meansquared spectrum are units
of power. Hmss = msspectrum(Hs,X) returns
a meansquare spectrum object containing the meansquare (power) estimate
of the discretetime signal X using the spectrum
object Hs . Default for real X is
the 'onesided' Nyquist frequency range and for
complex X the default is the 'twosided' Nyquist
frequency range.
Hmss contains a vector
of normalized frequencies W , at which the meansquare
spectrum is estimated. For real signals, the range of W is
[0,π] if the number of FFT points (NFFT )
is even, and [0,π) if NFFT is odd. For complex
signals, the range of W is [0,2π). To estimate
the spectrum on a vector of specific frequencies, see FreqPoints property
below.
The msspectrum method includes
these properties, which you can set using this msspectrum method
or via the msspectrumopts method. These properties
are listed here and described in the msspectrumopts section
below:
SpectrumType — 'onesided' or 'twosided'
NormalizedFrequency – normalizes
frequency between 0 and 1
Fs —
sampling frequency in Hz
NFFT —
number of FFT points
CenterDC —
shifts data and frequencies to center DC component
FreqPoints — 'All' or 'User
Defined'
FrequencyVector —
frequencies at which to compute spectrum
ConfLevel —
confidence level to calculate the confidence interval. Value must
be from 0 to 1. For example, Hmss = msspectrum(Hs,X,'FreqPoints','User Defined', FreqVector,fvect) returns
a meansquare spectrum object where the spectrum is calculated only
on the frequency points defined in the frequency vector, fvect . msspectrum(...) with
no output arguments plots the meansquare spectrum in dB.

msspectrumopts
 Hopts = msspectrumopts(Hs) returns
an object that contains options for the spectrum object Hs .
Hopts = msspectrumopts(Hs,X) returns
an object with dataspecific options and defaults.
You
can pass an Hopts options object as an argument
to the msspectrum method. Any individual option
you specify after the Hopts object overrides the
value in Hopts . For example, Hmss = msspectrum(Hs,X,Hopts, 'SpectrumType', 'twosided') overrides
the default SpectrumType value in Hopts . The
following properties apply to both msspectrumopts and msspectrum methods. Hmss
= msspectrum (..., 'SpectrumType', 'twosided') returns the
twosided meansquare spectrum. The spectrum length (NFFT) is computed
over [0,2π), or if Fs is specified, [0,Fs )
. Entering 'onesided' returns the onesided meansquare
spectrum, which contains the total signal power in half the Nyquist
range. Default is 'onesided' .
Hmss
= msspectrum(Hs,X,'NormalizedFrequency',true) returns a
meansquare spectrum object with frequency values normalized between
0 and 1. Default is true .
Hmss
= msspectrum(Hs,X,'Fs',Fs) returns a meansquare spectrum
object computed as a function of frequency, where Fs is
the sampling frequency in Hz. Note that you can set Fs only
if NormalizedFrequency is set to false .
Hmss = msspectrum(...,'NFFT',nfft) specifies
the number of FFT points to use. Valid values are a positive integer, 'Nextpow2' or 'Auto' . 'Nextpow2' uses
the next power of 2 greater than the input length or 256, whichever
is greater. 'Auto' uses the input length or 256,
whichever is greater. Default is 'Nextpow2' . Note
that for spectrum.welch , 'Nextpow2' and 'Auto' are
compared to the SegmentLength instead of the input
length.
Hmss = msspectrum (..., 'Centerdc', true) shifts
the data and frequency values so that the DC component is at the center
of the spectrum. Default is false .
To
estimate the spectrum on a vector of specific frequencies, first set
the number of frequency points to 'User Defined' ,
which replaces the NFFT property of msspectrum with
a FrequencyVector property.
Hopts.FreqPoints
= 'User Defined'
(Note that the default for FreqPoints is 'All' ,
which causes msspectrum to use the NFFT property
as described above.) Then, specify the frequency vector F to
use.
Hopts.FrequencyVector = F
(Note that the default value for FrequencyVector is 'Auto' .
In this case, the number of frequency points used follows the same
rule as described for NFFT 'Auto' above.) Hmms =
msspectrum(...,'ConfLevel',p) specifies the confidence level p for
computing the confidence interval, which is an estimate of the error
in the calculated meansquared spectrum. The confidence level (p )
is between 0 and 1. For example, Hmss = msspectrum(Hs,X,'ConfLevel',0.95) returns the
95% confidence interval.

psd
 Note that music and eigenvector spectrum
objects do not support the psd method. See the pseudospectrum method
below. The power spectral density (PSD) is intended for
continuous spectra. The integral of the PSD over a given frequency
band computes the average power in the signal in that frequency band.
In contrast to the msspectrum , the peaks in this
spectra do not reflect the power at a given frequency. The units of
the PSD are power per unit of frequency. See the avgpower method
of dspdata for more information. Hpsd = psd (Hs,X) returns a power
spectral density object containing the power spectral density estimate
of the discretetime signal X using the spectrum
object Hs . The PSD is the distribution of power
per unit frequency. Default for real X is 'onesided' and
for complex X is 'twosided' .
Hpsd contains
a vector of normalized frequencies W , at which
the PSD is estimated. For real signals, the range of W is
[0,π] if the number of FFT points (NFFT )
is even, and [0,π) if NFFT is odd. For complex
signals, the range of W is [0,2π).
The psd method
includes these properties, which you can set using this psd method
or via the psdopts method. These properties are
listed here and described in the psdopts section
below:
SpectrumType — 'onesided' or 'twosided'
NormalizedFrequency — normalizes
frequency between 0 and 1
Fs —
sampling frequency in Hz
NFFT —
number of FFT points
CenterDC —
shifts data and frequencies to center DC component
FreqPoints — 'All' or 'User
Defined'
FrequencyVector –
frequencies at which to compute spectrum
ConfLevel —
confidence level to calculate the confidence interval. Value must
be from 0 to 1. For example, Hmss = psd(Hs,X,'FreqPoints','User Defined', FreqVector,fvect) returns
a PSD object where the spectrum is calculated only on the frequency
points defined in the frequency vector, fvect . psd(...) with
no output arguments plots PSD in dB per unit frequency.

psdopts
 Hopts = psdopts(Hs) returns
an object that contains options for the spectrum object Hs .
Hopts = psdopts(Hs,X) returns
an object with dataspecific options and defaults.
You
can pass an Hopts options object as an argument
to the psd method. Any individual option you specify
after the Hopts object overrides the value in Hopts .
For example, Hpsd = psd(Hs,X,Hopts,'SpectrumType',
'twosided') overrides the SpectrumType value
in Hopts . The following properties
apply to both psdmopts and psd methods. Hpsd = psd (Hs,X,'SpectrumType','twosided') returns
the twosided power spectral density of X . The
spectrum length is NFFT and is computed over [0,2π) if Fs is
not specified or [0,Fs ) if Fs is
specified. Entering 'onesided' returns the onesided
PSD, which contains the total signal power.
Hmss
= psd(Hs,X,'NormalizedFrequency',true) returns a power spectral
density object with frequency values normalized between 0 and 1. Default
is true .
Hpsd = psd (...,'Fs',Fs) returns a power spectral density
object computed as a function of frequency, where Fs is
the sampling frequency in Hz.
Hmss = psd(...,'NFFT',nfft) specifies the number of
FFT points to use. Valid values are a positive integer, 'Nextpow2' or 'Auto' . 'Nextpow2' uses
the next power of 2 greater than the input length or 256, whichever
is greater. 'Auto' uses the input length or 256,
whichever is greater. Default is 'Nextpow2' . Note
that for spectrum.welch , 'Nextpow2' and 'Auto' are
compared to the SegmentLength instead of the input
length.
Hmss = psd (..., 'Centerdc', true) shifts
the data and frequency values so that the DC component is at the center
of the spectrum. Default is false .
To
estimate the spectrum on a vector of specific frequencies, first set
the number of frequency points to 'User Defined' ,
which replaces the NFFT property of psd with
a FrequencyVector property.
Hopts.FreqPoints
= 'User Defined'
(Note that the default for FreqPoints is 'All' which
causes psd to use the NFFT property
as described above.) Hmms = psd(...,'ConfLevel',p) specifies
the confidence level p for computing the confidence
interval, which is an estimate of the error in the calculated PSD.
The confidence level (p ) is between 0 and 1. For
example, Hmss = psd(Hs,X,'ConfLevel',0.95) returns
the 95% confidence interval.

pseudospectrum
 Note that this method is used for only music or eigenvector spectrum
objects. Hps = pseudospectrum(Hs,X) returns
an object containing the pseudospectrum estimate of the discretetime
signal X using the spectrum object Hs . Hs must
be a music or eigenvector object.
Default for real X is 'half' and
for complex X is the 'whole' Nyquist
frequency range.
Hps contains a vector
of normalized frequencies W , at which the pseudospectrum
is estimated. For real signals, the range of W is
[0,π] if the number of FFT points (NFFT )
is even, and [0,π) if NFFT is odd. For complex
signals, the range of W is [0,2π).
The pseudospectrum method
includes these properties, which you can set using this pseudospectrum method
or via the pseudospectrumopts method. These properties
are described below:
SpectrumRange — 'half' or 'whole'
NormalizedFrequency — normalizes
frequency between 0 and 1
Fs —
sampling frequency in Hz
NFFT —
number of FFT points
CenterDC —
shifts data and frequencies to center DC component
FreqPoints — 'All' or 'User
Defined'
FrequencyVector —
frequencies at which to compute spectrum For example, Hmss = psd(Hs,X,'FreqPoints','User Defined',
FreqVector,fvect) returns a PSD object where the spectrum
is calculated only on the frequency points defined in the frequency
vector, fvect . pseudospectrum(...) with
no output arguments plots the pseudospectrum in dB.

pseudospectrumopts
 Hopts = pseudospectrumopts(Hs) returns
an object that contains options for the spectrum object Hs .
Hopts = pseudospectrumopts(Hs,X) returns
an object with dataspecific options and defaults. You can pass an Hopts options
object as an argument to the pseudospectrum method.
Any individual option you specify after the Hopts object
overrides the value in Hopts . For example, Hpseudospectrum= pseudospectrum(Hs,X, Hopts,'SpectrumRange', 'whole') overrides
the SpectrumRange value in Hopts .
Hmps = pseudospectrum (..., 'SpectrumRange',
'whole') returns the pseudospectrum over the whole Nyquist
range. The spectrum length is NFFT and is computed over [0,2π)
if Fs is not specified or [0,Fs )
if Fs is specified. Entering 'half' returns
the pseudospectrum calculated over half the Nyquist range.
Hmss
= pseudospectrum(Hs,X,'NormalizedFrequency',true) returns
a pseudospectrum object with frequency values normalized between 0
and 1. Default is true .
Hps = pseudospectrum(Hs,X,'Fs',Fs) returns
a pseudospectrum object computed as a function of frequency, where Fs is
the sampling frequency in Hz.
Hps = pseudospectrum(...,'NFFT',nfft) specifies the
number of FFT points to use. Valid values are a positive integer, 'Nextpow2' or 'Auto' . 'Nextpow2' uses
the next power of 2 greater than the input length or 256, whichever
is greater. 'Auto' uses the input length or 256,
whichever is greater. Default is 'Nextpow2' .
Hps = pseudospectrum(...,'Centerdc',true) shifts
the data and frequency values so that the DC component is at the center
of the spectrum. The default value is false .
To
estimate the spectrum on a vector of specific frequencies, first set
the number of frequency points to 'User Defined' ,
which replaces the NFFT property of pseudospectrum with
a FrequencyVector property.
Hopts.FreqPoints
= 'User Defined'
(Note that the default for FreqPoints is 'All' ,
which causes pseudospectrum to use the NFFT property
as described above.) 
powerest
 Note that powerest is available only
for music and eigenvector spectrum
objects. POW = powerest(Hs,X) returns
a vector POW containing estimates of the powers
of the complex sinusoids in X . The input X can
be a vector or a matrix. If it is a matrix it can be a data matrix,
where $${{X}^{\prime}}^{*}X=R$$ or a correlation matrix R.
The value the InputType property of Hs determines
how X is interpreted. Hs must
be a music or eigenvector spectrum
object.
[POW,W]=powerest(Hs,X) returns POW and
a vector W of the frequencies in rad/sample of
the sinusoids in X .
[POW,F]=powerest(Hs,X,Fs) returns POW and
a vector F of the frequencies in Hz of the sinusoids
in X . Fs is the sampling frequency.
