Toni: moved Programmer Guide/SPU Reference/PEAKS - spectral peak picking to Programmer Guide/SPU Reference/PEAKS

2011-04-28T10:05:28Z

moved Programmer Guide/SPU Reference/PEAKS - spectral peak picking to Programmer Guide/SPU Reference/PEAKS

← Older revision	Revision as of 12:05, 28 April 2011
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Admin: 1 revision: Initial import

2010-11-18T16:31:54Z

1 revision: Initial import

← Older revision	Revision as of 18:31, 18 November 2010
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193.171.195.8: initial import

2010-05-17T13:05:27Z

initial import

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====PEAKS - spectral peak picking====

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

<code>PEAKS <var>X Y TH XMIN XMAX M W I SORT</var></code>

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

{|
|-
|X,Y
|vector of x/y<nowiki>-</nowiki>value pairs
|-
|TH
|threshold value or vector
|-
|XMIN,XMAX
|lower and upper boundary of peak search interval
|-
|M
|maximum number of peaks
|-
|W, I
|peak detection (±M pts., W>0) and interpolation (±I, 0£I£W) width
|-
|SORT
|sort option for output values
|}

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

{|
|-
|<var>X,Y</var>
|x/y<nowiki>-</nowiki>values of peaks (vectors of length M)
|-
|M
|actual number of detected peaks (0..M)
|}

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

This atom searches the function given by the X/<var>Y</var> inputs for local maxima (peaks). For the peak detection, the following conditions are used:

point (<var>X</var>i, <var>Y</var>i) is a peak if:

<var>XMIN</var> £ <var>X</var>i £ <var>XMAX</var><var>Y</var>i > <var>TH</var>i<var>Y</var>i-1 < <var>Y</var>i and <var>Y</var>i+1 < <var>Y</var>i<var>Y</var>i-j-1 £ <var>Y</var>i-j and <var>Y</var>i+j+1 £ <var>Y</var>i+j for j=1..<var>W</var>-1If the input <var>TH</var> is a number, all threshold values <var>TH</var>i are set to this value. If the interpolation width <var>I</var> is a positive value (1..<var>W</var>), a parabolic interpolation is used to compute the x- and y-values of the local maxima. For the interpolation, the three points i-<var>I</var>, i and i+<var>I</var> are used. The x/y values and the number of detected peaks are stored in the outputs. If fewer than <var>M</var> peaks are found, the remaining values of the <var>X</var>/<var>Y</var> outputs are set to 0. E.g. this atom can be used for the peak detection for the <code>[[Programmer Guide/SPU Reference/F0HGRID - f0 extraction with harmonic grid|F0HGRID]]</code> and <code>[[Programmer Guide/SPU Reference/FORMANTS - formant extraction|FORMANT]]</code> atoms.

Programmer Guide/SPU Reference/PEAKS - Revision history

Toni: moved Programmer Guide/SPU Reference/PEAKS - spectral peak picking to Programmer Guide/SPU Reference/PEAKS

Admin: 1 revision: Initial import

193.171.195.8: initial import