Questions tagged [wavelet-analysis]

Questions on the wavelet analysis functions of Mathematica.

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8
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1answer
320 views

Please explain this syntax: GaborWavelet[6][“FourierFactor”]

I've been using Mathematica for some years, yet I'm befuddled by this statement: GaborWavelet[6]["FourierFactor"] It appears to give the center frequency ...
7
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2answers
234 views

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

This question was asked in 2013, but didn't get an answer. Can Mathematica plot the cone of influence in wavelet analysis. Matlab will do it. Follow up question. Does it make good mathematical ...
0
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1answer
24 views

Cannot take DWT of parsed data

I have some data in foo.tsv, and I would like to take the DiscreteWaveletTransform of one column. My data looks like this: ...
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0answers
23 views
5
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2answers
188 views

Getting rid of “glitches” in DiscreteWaveletTransform-de-noised data

Typical glitch Dear all, I have been using discrete wavelet transforms for de-noising simulated (and real) radiation counting data and from time to time encounter "glitches" in the resulting de-...
0
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0answers
28 views

Calculate Energy of signal by coefficients of continuous wavelet transform

I have applied ContinuousWaveletTransform to my data. And now I want to calculate the Energy of signal in accordance with Parseval theorem To find Energy I would like to use quadrature formula: . I ...
2
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2answers
74 views

Integral of a Wavelet function

I ran into problems integrating a function which contains both an If condition and a Wavelet which is an ...
3
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1answer
69 views

<<Wavelets`Wavelets Not Found [closed]

please i'm a student and i need help in my project which is based on an already existing program. The problem that the program is ancient( Mathematica 5.0) and doesn't fit with the new versions of ...
2
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2answers
72 views

WaveletListPlot: Broken in 11.2?

I'm trying to create a WaveletListPlot, following the reference code exactly: ...
3
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1answer
280 views

Solve 1D Wave Equation

I wanna model 1D wave equation and plot it, Here is my try so far, ...
1
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1answer
97 views

Numerical solution to approximate the singular integration using collocation method

I am working to solve "numerically" the following integral equation IE: u[x]=f[x]+Integrate[(1/(x-t)^(1/4))*u[t],{t,0,x}]+Integrate[(1/(x-t)^(1/4))*u[t],{t,0,1}] ...
2
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0answers
101 views

Coefficients of continuous wavelet transform

I am fiddling with wavelet coefficients in Mathematica, and for simplicty only a real valued Wavlet. Lets say we have the data: ...
0
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1answer
109 views

Getting errors NIntegrate::nlim and NIntegrate::slwcon [closed]

Here is the modified question: First: Define phi[x_]:=Piecewise[{{1, 0 <= x < 1}}, 0] ...
1
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0answers
93 views

Revert image fusion using discrete wavelet transform

How can I extract a hidden image using discrete wavelet transform? I have used the function ImageFusion from this site to hide an image inside another one. ...
2
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3answers
150 views

Integrating a function containing a wavelet

How do I evaluate the integral c? ...
4
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2answers
152 views

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

So, I use the following code to carry out the discrete wavelet transform on an image of Lena. I am interested in then doing some changes to a single image out of the obtained 4. How do I extract any ...
1
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0answers
109 views

wavelet fourier transform

I want to do wavelet Fourier transform of my data but I have few doubts in this. 1)first of all what is octive and voice command here when i am changing value according to that my plot is changing but ...
1
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0answers
241 views

Comparison of Discrete Cosine Transform and Discrete Wavelet Transform

I would like to compare the sorted coefficients of the Discrete Cosine Transform with that of the Discrete Wavelet Transform using the Haar wavelets. From theory, the discrete wavelet transform offers ...
2
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1answer
176 views

Computing FundamentalFrequency

How does Mathematica use AudioLocalMeasurements to compute the fundamental frequency? Is there any formula? I can't seem to find what method Mathematica makes use ...
3
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1answer
210 views

Wavelet filter artifact

I would like to denoise some data using wavelet filters. My current approach is to employ the stationary wavelet transform with Haar wavelets. However, this leads to undesirable artifacts at the top ...
3
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1answer
162 views

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

Actually this question is related with this post,but this is about point of 3-dimension ...
1
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2answers
131 views

How to detect the singular value with wavelet analysis

I have a series data data=Uncompress[ FromCharacterCode[Flatten[ImageData[Import["http://i.stack.imgur.com/ApipY.png"], "Byte"]]]]; We can show it ...
6
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2answers
228 views

How to calculate the amount of offset about two list

You can get my data by this code {data1, data2} = Uncompress[FromCharacterCode@ Flatten[ImageData[Import["https://i.stack.imgur.com/ShSMY.png"], "Byte"]]]; We ...
1
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0answers
162 views

Find wavelet transform coefficients in L1 norm [closed]

For my masters task I have to perform a Haar wavelet transform using an L1 norm. But Mathematica's built-in wavelet library can work only with L2 norm space. I tried to do this: ...
4
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0answers
98 views

Why does Continuous Wavelet Transform have phase information at high frequencies?

I'm playing around with ContinuousWaveletTransform using a sine wave of a constant frequency: ...
8
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2answers
308 views

How to detect discolorations in an image?

I'm evaluating the technical quality of an images and I'd like to scan it for defects from dirty sensors. Are there any filters to quickly detect a blob of discoloration? Here are a few examples:
2
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1answer
781 views

How to generate a Wavelet Matrix?

The Wavelet Matrix, also called the Haar matrix, is very useful. We can find some useful information in MathWorld on how to generate it, but this document is too hard for me. From my reading of the ...
2
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0answers
901 views

Detrending a time-series by means of Discrete Wavelet Transform

I plot a time-series for observation as you can see in the plot: I tried to detrend the time series by 3 different approaches which are: 1) differences, 2) detrended fluctuation analysis, and 3) ...
1
vote
1answer
104 views

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

The question is why can data be recovered perfectly from a discrete wavelet transform with a Haar wavelet but not with some Battle-Lemarie wavelets? A simple example with the ...
2
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0answers
67 views

Modified WaveletImagePlot

When performing Wavelet Transform ...
4
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1answer
290 views

How to obtain amplitude and phase of tidal data using wavelets

I have a time series of tidal data for one month and success with identifying tidal characteristic such as semidiurnal or diurnal spring and neap position power spectrum However, I don't have ...
5
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1answer
121 views

InverseWaveletTransform not recreating the original image exactly

I am trying to do DWT steganography. I first obtain the DiscreteWaveletTransform of the image as follows ...
1
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0answers
220 views

Wavelet Data Visualization (modus and phase) ListPlot [closed]

Due to ContinuousWaveletTransform[...] I can obtain information about wavelet-coefficient for example ...
4
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2answers
423 views

How to define a new wavelet type?

I have a problem in understanding how to create my own wavelets in Mathematica's wavelet framework. There is a tutorial. I have read the tutorial, but I don’t understand what exactly is needed to ...
9
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1answer
3k views

Create “Ostagram” like Images using Wavelet Transforms

I am trying to make an "ostagram" like image using wavelet transforms and image keypoints. See the following link: https://www.facebook.com/ostagram/ This is done using neural networks, which I at ...
25
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3answers
2k views

Detecting components in timeseries

I'm looking at this sequence of values: I'd like to detect the points where the center of the time-series shifts (around x=1000 and x=2000). Many of the transforms and smoothing methods I have tried ...
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0answers
118 views

Problem with DiscreteWaveletTransform for DaubechiesWavelet

I am trying to use Mathematica's wavelet transform. In preparation I entered: ...
1
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2answers
102 views

InverseWaveletTransform of a list of rules

I want to extract coefficient images from a DiscreteWaveletTransform and replace them by modified images of the same dimensions. However, when I use ...
2
votes
1answer
157 views

How many arguments does a function require, and how to use that in `Manipulate`

The goal is to vary the order parameters in wavelet transforms in the Manipulate environment. The various transformations have arguments of different rank. For ...
8
votes
1answer
2k views

How to extract notes and chords from audio?

I have a 3-second recording of a guitar chord which you can safely download here. I'm trying to use Mathematica's wavelet features to find out the notes in the chord, at least the docs says that ...
6
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0answers
1k views

Wavelet Transform Modulus Maxima (WTMM) method

Has anyone already coded the Wavelet Transform Modulus Maxima (WTMM) method for computing the singular spectrum using multi fractal formalism in Mathematica? The goal is to analyse 1D, 2D and 3D data....
2
votes
1answer
587 views

Wavelet transform of data with sliders

I saw a beautiful application of wavelets applied to a randomly created data series of about 500 data points. It used the Haar wavelet and had two sliders. The first slider allowed the user to view a ...
3
votes
1answer
2k views

Wavelet vs instantaneous power spectrum

Following on from a previous question posted by @xslittlegrass and answered by @Sector and others, Extracting information from the result of ContinuousWaveletTransform I'd like to know if it is ...
4
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1answer
375 views

Wavelet expansion of given function (as opposed to DWT of given data)

To illustrate, say I take the following function (the reason for the square root will be apparent soon) ...
2
votes
1answer
151 views

LiftingWaveletTransform with irregular grids

One of the properties mentioned in the literature about the lifting wavelet transform is that it can be applied on irregular meshes or grids (i.e. not equally spaced samples); but I don't seem to see ...
1
vote
1answer
162 views

Calculate support of given wavelet

I am calculating approximations using wavelets but outside the multi resolution analysis framework; particularly, I am not using the built-in wavelet transforms. Still, I need to calculate ...
17
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3answers
622 views

Disentangling the data

An experiment yields a functional dependence on two variables $F(x,y)$, can be imagined as a 2D map. It is known that the function can be factored as follows $F(x,y)=fx(x) gy(y) +gx(x) fy(y)$. Given ...
6
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3answers
2k views

Signal processing by means of WaveletTransform

I updated my question to explain what I want. I have the voltage-time curve from the real industial object. This curve was gotten from the digital oscilloscope: As you can see it has hight-frequency ...
1
vote
1answer
300 views

Is wavelet a Nonlinear transform, or Not? [closed]

Is wavelet a Nonlinear transform, or Not? specifically, continuous wavelet transform with morlet function. I am studying behavior of a dynamic system, and it has nonlinear behaviour. can I employ ...
12
votes
1answer
571 views

Wavelet transform order problem

I have a signal that I'm trying to study its time-frequency features by continuous wavelet transform. By choosing different wavelet order, I get some differences in the results. ...