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# Tag Info

## Hot answers tagged wavelet-analysis

13 votes
Accepted

### Please explain this syntax: GaborWavelet[6]["FourierFactor"]

Quite often, a Mathematica object can have properties, and typically you can find out what properties (or methods) are available by using "Properties" or "Methods". For example: <...
• 131k
9 votes
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### Is there a way to add a cone of influence to waveletscalogram?

Cone of influence shows how boundary of data sample affects wavelet coefficients for the chosen wavelets family. To reproduce Figure from mathworks page we first prepare data with an impulse on the ...
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9 votes
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### Computing FundamentalFrequency

You can use Cepstrum,Wiki says It was originally invented for characterizing the seismic echoes resulting from earthquakes and bomb explosions. It has also been used to determine the fundamental ...
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6 votes
Accepted

### How to calculate the amount of offset about two list

Could also use ListCorrelate. ...
• 59.3k
6 votes

### Integrating a function containing a wavelet

Here's how to get Integrate[] to work. As you may have already noticed, the result of WaveletPhi[DaubechiesWavelet[6], x] is a <...
6 votes

### Create "Ostagram" like Images using Wavelet Transforms

A example in the StationaryWaveletTransform(Application/ImageFusion) seem can do this ...
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5 votes

### Integrating a function containing a wavelet

When integrating an interpolating function, I think it's simplest to just use NDSolveValue: ...
• 131k
5 votes
Accepted

Try this ...
• 146k
5 votes

### Integrating a function containing a wavelet

Try it with NIntegrate, as you want to obtain a numeric result. Further, phiD6[x]is a ...
5 votes
Accepted

### How to detect the singular value in 3-dimension with wavelet analysis

In general, detecting anomalies is pretty straightforward assuming you know the distribution of your data. In this case, I will estimate the distribution for each dimension in your data, then ...
• 2,357
5 votes
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### How to generate a Wavelet Matrix?

Update-2: More compact version proposed by J. M. with the matrix normalized: ...
• 7,505
5 votes

### How to calculate the amount of offset about two list

We can use Fourier techniques (cross-correlation) to estimate a misalignment between the signals. Import the data ...
• 16.8k
5 votes
Accepted

### Identifying an envelope function of a wave-packet

We first need some data: d = Table[Exp[-t^2/10] Sin[10 t] Sin[t], {t, -7, 7, 0.01}]; ListLinePlot[d, PlotRange -> All] Then we need a function that determines the local min/max: ...
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4 votes

### Is there a way to add a cone of influence to waveletscalogram?

Let us start with clarifying terminology since this is a really big problem in this community. Terminology is well done in this text: A Practical Guide to Wavelet Analysis by Christopher Torrence and ...
• 4,088
4 votes

### <<Wavelets`Wavelets Not Found

The old Wavelet Explorer has been discontinued. The newer built-in Wavelet Analysis functionality replaces it, with a conversion tutorial here.
4 votes

### Getting rid of "glitches" in DiscreteWaveletTransform-de-noised data

I do not think that this is a bug. It is quiet normal to get "glitches" during the IDWT of thresholded wavelet coefficients. In some cases it is obvious from the structure of the data, in other cases ...
• 1,533
4 votes

### One dimensional wave equation -numerical vs analitcal solution?

The piece-wise domain shown in the image doesn't seem to be correct. The second one in particular, though you typed in correctly in your code, should be $$(2n+1)l/c<t\leq(2n+2)l/c\;.$$ I assume ...
• 1,281
4 votes

### One dimensional wave equation -numerical vs analitcal solution?

This is an answer and an extended comment. Your question is well-written and clearly explains the issue. But I think the issue is just a wrong use of the Piecewise ...
• 41.9k
3 votes
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### Getting rid of "glitches" in DiscreteWaveletTransform-de-noised data

Update 30/05/2020: this answer explains the motivation for thinking it's a bug - but see @demm's answer. There are good reasons the spikes appear and are not thresholded out by default. I'm leaving ...
• 25.5k
3 votes

### Integral of a Wavelet function

The approach taken in this answer is also applicable to this problem. Construct the function to be integrated: ...
3 votes

### Integral of a Wavelet function

You introduce an unnecessary dummy variable x. This is my version ...
• 16.8k
3 votes

### How to detect discolorations in an image?

I'm still working on it and there still can be a lot improvements in my work, but I think it's a good thing to let you know there's still someone working on this interesting question. ...
• 9,630
3 votes

### How to detect discolorations in an image?

If you can generate desired images, then sensor noise or surface defects can be imaged by use of a small aperture (say f/22) and making two images of a reasonably uniform background. A visual flicker ...
3 votes

### Defining a new wavelet (Fibonacci wavelet)

You need to (1) use a different integration variable in the integral (which is Integrate, not Int) and (2) use an immediate ...
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3 votes

### Image Segmentation for Grid and fence of cage in Frequency Domain

Trying to separate out these fence by spectrum doesn't look easy: ...
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3 votes

### Identifying an envelope function of a wave-packet

The envelope can be detected using EstimatedBackGround after v10. A demo is available here. Let's say the signal is defined as: ...
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2 votes

### How to recover data from a DiscreteWaveletTransform with Battle-Lemarie Wavelets?

When taking transforms and their inverses, it is necessary to use the same options in both operations. In your case, you need to tell the InverseWaveletTransform to ...
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2 votes

### How to obtain amplitude and phase of tidal data using wavelets

ListPlot[Flatten[data]] Periodogram[Flatten[data]] ...
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2 votes

### How to extract a single image from the output of the DiscreteWaveletTransform[]?

As I noted in the comments, the docs mention how to obtain the component images used in WaveletImagePlot[]: ...
2 votes
Accepted

### Wavelet filter artifact

The observed boundary artifacts can be reduced in part by applying a wavelet threshold to smooth the data noise. Also, the filtered wavelet can be composed as a mixture of fluctuations components in a ...
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