LTPDA Toolbox™ contents Method: ao/kstest   Method: ao/lcpsd

Method ao/lcohere

  LCOHERE implement magnitude-squadred coherence estimation on a log frequency axis.
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  DESCRIPTION: LCOHERE implement coherence estimation on a log frequency axis.
               The estimate is done by taking 
               the ratio of the CPSD between the two inputs, Sxy, divided by 
               the product of the PSDs of the inputs, Sxx and Syy,              
               and is either magnitude-squared: (abs(Sxy))^2 / (Sxx * Syy) 
               or complex value: Sxy / sqrt(Sxx * Syy)
               Here x is the first input, y is the second input
 
  CALL:        b = lcohere(a1,a2,pl)
 
  INPUTS:      a1   - input analysis object
               a2   - input analysis object
               pl   - input parameter list
 
  OUTPUTS:     b    - output analysis object
 
  Parameters Description
 
  References:  "Improved spectrum estimation from digitized time series
                on a logarithmic frequency axis", Michael Troebs, Gerhard Heinzel,
                Measurement 39 (2006) 120-129.
 
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Method Details
Access public
Defining Class ao
Sealed 0
Static 0

Parameter Description

Sets for this method …
Default

Default
no description
Key Default Value Options Description
lcohere
WIN 'BH92'
  • 'Rectangular'
  • 'Welch'
  • 'Bartlett'
  • 'Hanning'
  • 'Hamming'
  • 'Nuttall3'
  • 'Nuttall4'
  • 'Nuttall3a'
  • 'Nuttall3b'
  • 'Nuttall4a'
  • 'Nuttall4b'
  • 'Nuttall4c'
  • 'BH92'
  • 'SFT3F'
  • 'SFT3M'
  • 'FTNI'
  • 'SFT4F'
  • 'SFT5F'
  • 'SFT4M'
  • 'FTHP'
  • 'HFT70'
  • 'FTSRS'
  • 'SFT5M'
  • 'HFT90D'
  • 'HFT95'
  • 'HFT116D'
  • 'HFT144D'
  • 'HFT169D'
  • 'HFT196D'
  • 'HFT223D'
  • 'HFT248D'
  • 'Kaiser'
  • 'levelledHanning'
 The window to be applied to the data to remove the discontinuities at edges of segments. [default: taken from user prefs]
Only the design parameters of the window object are used. Enter a string value containing the window name e.g.
plist('Win', 'Kaiser', 'psll', 200)
plist('Win', 'BH92')
PSLL 200 none The peak sidelobe level for Kaiser windows.
Note: it is ignored for all other windows
OLAP -1 none The segment percent overlap [-1 == take from window function]
ORDER, N 0
  • -1
  • 0
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
 The order of segment detrending:
  • -1 - no detrending
  • 0 - subtract mean
  • 1 - subtract linear fit
  • N - subtract fit of polynomial, order N
DROP WINDOW SAMPLES 1
  • 1
  • 0
 Drop the recommended (by the window) number of samples of the final computed spectral series.
TIMES, SPLIT [] none The time range to analyze. If not empty, sets the time interval to operate on.
As in ao/split, the interval can be specified by:
  • a vector of doubles
  • a timespan object
  • a cell array of time strings
  • a vector of time objects
KDES 100 none The desired number of averages.
JDES 1000 none The desired number of spectral frequencies to compute.
LMIN 0 none The minimum segment length.
TYPE 'C'
  • 'C'
  • 'MS'
 type of output scaling. Choose from:
  • MS - Magnitude-Squared Coherence:
    (abs(Sxy))^2 / (Sxx * Syy)
  • C - Complex Coherence:
    Sxy / sqrt(Sxx * Syy)

Example
plist('WIN', 'BH92', 'PSLL', [200], 'OLAP', [-1], 'ORDER', [0], 'DROP WINDOW SAMPLES', [true], 'TIMES', [[]], 'KDES', [100], 'JDES', [1000], 'LMIN', [0], 'TYPE', 'C')

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Some information of the method ao/lcohere are listed below:
Class name ao
Method name lcohere
Category Signal Processing
Package name ltpda
VCS Version 967b0eec0dece803a81af8ef54ad2f8c784b20b2
Min input args 2
Max input args -1
Min output args 1
Max output args -1
Can be used as modifier 0
Supported numeric types {'double'}



Method: ao/kstest  Method: ao/kstest   Method: ao/lcpsd Method: ao/lcpsd

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