Summary

- Plugin name : Continuous Wavelet Analysis
- Version : 1.0
- Author : Quentin Barthelemy
- Company : Mensia Technologies SA
- Short description : Performs a Time-Frequency Analysis using CWT.
- Documentation template generation date : Dec 3 2018
Description
Performs a Time-Frequency Analysis using Continuous Wavelet Transform.
The Continuous Wavelet Transform (CWT) provides a Time-Frequency representation of an input signal, using Morlet, Paul or derivative of Gaussian wavelets.
Considering an input signal , composed of
channels and
temporal samples, this plugin computes the CWT of this signal
, composed of
channels,
scales and
temporal samples. For the
channel, the
scale
and the
sample, the Time-Frequency representation is defined as:
where is the normalized wavelet,
is the complex conjugate and
is the sampling period.
Using the inverse relation between wavelet scale and Fourier frequency
, output is finally defined as:
with being the imaginary unit.
Output can be visualized with a Instant Bitmap (3D Stream).
Inputs
1. Input signal
An input multichannel signal , composed of
channels and
temporal samples.
- Type identifier : Signal (0x5ba36127, 0x195feae1)
Outputs
1. Amplitude
An output spectral amplitude (absolute value) .
- Type identifier : Time-frequency (0x5a90816b, 0xff2aff72)
2. Phase
An output spectral phase , in radians.
- Type identifier : Time-frequency (0x5a90816b, 0xff2aff72)
3. Real Part
An output real part of the spectrum .
- Type identifier : Time-frequency (0x5a90816b, 0xff2aff72)
4. Imaginary Part
An output imaginary part of the spectrum .
- Type identifier : Time-frequency (0x5a90816b, 0xff2aff72)
Settings
1. Wavelet type
This setting defines the type of the wavelet:
Morlet:
Paul:
derivative of Gaussian:
- Type identifier : Continuous Wavelet Type (0x09177469, 0x52404583)
- Default value : [ Morlet wavelet ]
2. Wavelet parameter
This setting defines the wavelet parameter:
- Morlet wavelet: nondimensional frequency
, real positive parameter value. Values between 4.0 and 6.0 are typically used.
- Paul wavelet: order
, positive integer values inferior to 20. Default value is 4.
- Derivative of Gaussian wavelet: derivative
, positive even integer values. Value 2 gives the Marr or Mexican hat wavelet.
- Type identifier : Float (0x512a166f, 0x5c3ef83f)
- Default value : [ 4 ]
3. Number of frequencies
This setting defines the number of frequencies of the CWT.
- Type identifier : Integer (0x007deef9, 0x2f3e95c6)
- Default value : [ 60 ]
4. Highest frequency
This setting defines the highest frequency of the CWT.
- Type identifier : Float (0x512a166f, 0x5c3ef83f)
- Default value : [ 35 ]
5. Frequency spacing
This setting is related to the frequency non-linear spacing of the CWT.
- Type identifier : Float (0x512a166f, 0x5c3ef83f)
- Default value : [ 12.5 ]
Examples
Miscellaneous
Reference:
C Torrence and GP Compo, A Practical Guide to Wavelet Analysis, Bulletin of the American Meteorological Society, vol. 79, pp. 61–78, 1998
Generated on Tue Jun 26 2012 15:25:54 for Documentation by
