spectrum.mtm
Thomson multitaper spectrum
Syntax
Hs = spectrum.mtm
Hs = spectrum.mtm(TimeBW)
Hs = spectrum.mtm(DPSS,Concentrations)
Hs = spectrum.mtm(...,CombineMethod)
Description
Note
The use of spectrum.mtm
is not recommended.
Use pmtm
instead.
Hs = spectrum.mtm
returns
a default Thomson multitaper spectrum object, Hs
that
defines the parameters for the Thomson multitaper spectral estimation
algorithm, which uses a linear or nonlinear combination of modified
periodograms. The periodograms are computed using a sequence of orthogonal
tapers (windows in the frequency domain) specified from discrete prolate
spheroidal sequences (dpss
).
This object uses the following default values:
Property Name | Default Value | Description |
---|---|---|
|
| Product of time and bandwidth for the discrete prolate spheroidal sequences (or Slepian sequences) used as data windows |
|
| Algorithm for combining the individual spectral estimates.
Valid values are |
Hs = spectrum.mtm(TimeBW)
returns
a spectrum object, Hs
with the specified time-bandwidth
product.
Hs = spectrum.mtm(DPSS,Concentrations)
returns
a spectrum object, Hs
with the specified dpss data
tapers and their concentrations.
Note
You can either specify the time-bandwidth product (TimeBW
)
or the DPSS
data tapers and their Concentrations
.
See dpss
and pmtm
for more information.
Hs = spectrum.mtm(...,CombineMethod)
returns
a spectrum object, Hs
, with the specified method
for combining the spectral estimates. Refer to the table above for
valid CombineMethod
values.
Examples
Define a cosine of 200 Hz, add noise and view its power spectral density using the Thomson multitaper algorithm with a time-bandwidth product of 3.5.
Fs=1000; t=0:1/Fs:.3; x=cos(2*pi*t*200)+randn(size(t)); Hs=spectrum.mtm(3.5); psd(Hs,x,'Fs',Fs)
The above example could be done by specifying the data tapers and concentrations instead of the time-bandwidth product.
Fs=1000; t=0:1/Fs:.3; x=cos(2*pi*t*200)+randn(size(t)); [e,v]=dpss(length(x),3.5); Hs=spectrum.mtm(e,v); psd(Hs,x,'Fs',Fs)
Version History
Introduced before R2006a
See Also
periodogram
| pmtm
| pwelch