Toni: moved Programmer Guide/SPU Reference/WLANA - general wavelet analysis to Programmer Guide/SPU Reference/WLANA

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moved Programmer Guide/SPU Reference/WLANA - general wavelet analysis to Programmer Guide/SPU Reference/WLANA

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====WLANA - general wavelet analysis====

A general wavelet analysis SPAtom (Project: MBBM/VA - WLLib).

=====Usage:=====

<code>SPU WLANA <var>WAVE</var> <var>HOPSIZE</var> <var>ITYPE</var> <var>MAXSIZE</var> <var>FTYPE</var> <var>FCNT</var> <var>FPAR1</var> <var>FPAR2</var> <var>WTYPE</var> <var>F0</var> <var>ACUT</var> <var>ORDER</var> <var>USEDS</var> <var>OTYPE</var> <var>AMAX</var> <var>AREF</var></code>

=====Inputs:=====

;<var>WAVE</var>

:The input signal wave item (mono)

;<var>HOPSIZE</var>

:The distance between frames in samples

;<var>ITYPE</var>

:The input frame alignment (values: BEGIN, CENTER)

;<var>MAXSIZE</var>

:The maximum signal queue length

;<var>FTYPE</var>

:The frequency bin definition type (values: RANGEQ, RANGED, DELTA, QUOTIENT, VECTOR)

;<var>FCNT</var>

:The number of bins. The default is 1.

;<var>FPAR1, FPAR2</var>

:The frequency bin definition parameters

;<var>WTYPE</var>

:The type of wavelet function. The following values are supported:

:MORLET|GAUSSGENERAL|LAPLACE|GAUSSNDERIV|MEXICANHAT|GOUPILLAUD|MORLETII

;<var>F0</var>

:The number of sin/cos cycles per window. It should be in the range <code>2<</code><var>F0</var><code><7</code>. This parameter has no meaning for wavelet types GAUSSNDERIV and MEXICANHAT. The default is 5.

;<var>ACUT</var>

:The filter length relative to the Gaussian function. The value should be in the range <code>1<</code><var>ACUT</var><code><3</code>. The default is 3.

;<var>ORDER</var>

:Only used for GAUSSGENERAL and GAUSSNDERIV wavelets.The default is 2. For GAUSSGENERAL wavelets, <var>ORDER</var> is the exponent (power) and must be >= 1 and in the range <code>1<</code><var>ORDER</var><code><4</code>. For GAUSSNDERIV wavelets, <var>ORDER</var> is the derivation order and must be >=1 and is converted to the nearest integer.

;<var>USEDS</var>

:The use downsampling (values: YES, NO). If turned on,

;<var>OTYPE</var>

:The type of output spectrum (values: REALIMAG|LINAMPPHASE|LOGAMPPHASE)

;<var>AMAX</var>

:An amplitude value > 0. The default is 1.

;<var>AREF</var>

:A reference amplitude > 0. The default is 1.

=====Outputs:=====

;<var>Y1</var>

:The real part or amplitude

;<var>Y2</var>

:The imaginary part or phase

;<var>F</var>

:The frequency bins

;<var>LMAX</var>

:The maximum frame length in samples

;<var>I</var>

:The number of processed frames

;<var>N</var>

:The maximum number of frames

;<var>SR</var>

:The sampling rate in Hz

=====Function:=====

Downsampling

If enabled, the wavelet spectrum is computed from the highest to the lowest bin (nFBins-1, .., 0) and on each bin i where f[i] fulfills the switch criterion defined below, a 1:2 downsampling is applied to the signal.

switch criterion:

[[File:5505.png]]

where:

f[i] - frequency of bin i

dSRate - sampling rate

dDFStep - normalized downsampling step switch frequency

D - current number of downsampling steps, starts with 0 (= no downsampling) and is incremented by 1 for each downsampling step

A FIR filter is used for anti-aliasing. The length of this filter depends on the cutoff frequency (parameter dDFCut). The downsampling frequency parameters are normalized frequencies (= scaled by 1/dSRate).

Each downsampling step increases the frame length in the following way:

[[File:5506.png]]

where:

LD - maximum frame length for step D (=nDown..1); Note: LnDown is the length of the wavelet for the lowest frequency bin at the highest downsampling step

L0 - is the required frame length for the original sampling rate

M - number of filter coefficients (half filter length)

Programmer Guide/SPU Reference/WLANA - Revision history

Toni: moved Programmer Guide/SPU Reference/WLANA - general wavelet analysis to Programmer Guide/SPU Reference/WLANA

Admin: 1 revision: Initial import

193.171.195.8: initial import