LTPDA Toolbox™ contents Method: ao/fft   Method: ao/filtSubtract

Method ao/fftfilt

  FFTFILT overrides the fft filter function for analysis objects.
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  DESCRIPTION: FFTFILT overrides the fft filter function for analysis objects.
               Applies the input filter to the input analysis
               object in the frequency domain. 
  
 
  CALL:        >> b = fftfilt(a,smodel); b = fftfilt(a,plist('filter',smodel)) 
               >> b = fftfilt(a,mfir); b = fftfilt(a,plist('filter',mfir))
               >> b = fftfilt(a,miir); b = fftfilt(a,plist('filter',miir))
               >> b = fftfilt(a,ltpda_tf); b = fftfilt(a,plist('filter',ltpda_tf))
               >> b = fftfilt(a,plist('filter',c)) % c is an AO used as a
                  filter
 
  INPUTS:      
                    a - input analysis object
       one of
               smodel - a model to filter with. The x-dependency must
                            be on frequency ('f').
                 mfir - an FIR filter
                 miir - an IIR filter
                 tf   - an ltpda_tf object
                        including:
                          - pzmodel
                          - rational
                          - parfrac
                   ao - a frequency-series AO. This must have the
                        correct frequency base to match the FFT'd input
                        data. You must input it in a plist
 
  OUTPUTS:
               b    - output analysis object containing the filtered data.
 
  Parameters Description
  
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Method Details
Access public
Defining Class ao
Sealed 0
Static 0

Parameter Description

Sets for this method …
custom filter
standard type filter

custom filter
no description
Key Default Value Options Description
fftfilt
NPAD [] none Number of bins for zero padding.
FILTER '' none The filter to apply to the data.
INITIAL CONDITIONS {} [0x0] none A cell containing the arrays of initial conditions, one for each system being solved, starting from the lower order to the maximum allowed. It assumed that the underlying system follows a linear differential equation with constant coefficients. For example, if the system is the Newton 2nd-order equation of motion, than the array contains the initial position and the initial velocity.

Example
plist('NPAD', [[]], 'FILTER', '', 'INITIAL CONDITIONS', cell(0,0))

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standard type filter
no description
Key Default Value Options Description
fftfilt
NPAD [] none Number of bins for zero padding.
TYPE 'lowpass'
  • 'highpass'
  • 'lowpass'
  • 'bandpass'
  • 'bandreject'
 Choose the filter type.
FC [0.10000000000000001 0.40000000000000002] none The roll-off frequency [Hz].
GAIN 1 none The gain of the filter.
IUNITS '' none The input units of the filter.
OUNITS '' none The output units of the filter.

Example
plist('NPAD', [[]], 'TYPE', 'lowpass', 'FC', [[0.10000000000000001 0.40000000000000002]], 'GAIN', [1], 'IUNITS', '', 'OUNITS', '')

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



Method: ao/fft  Method: ao/fft   Method: ao/filtSubtract Method: ao/filtSubtract

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