Questions tagged [wavelet-analysis]

Questions on the wavelet analysis functions of Mathematica.

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How to plot time-frequency evolution based on zero crossings?

In a paper that analyzes the data from GW150914, a time-frequency plot was shown. The paper proposes that, quote: An approximate version of the time-frequency evolution can also be obtained directly ...
Halcyon Mo's user avatar
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How to extract data from wavelet scalogram?

I've read several topics here concerning wavelets. Especially this one is very useful where in the answer is explained how to convert default Mathematica scalogram into useful one (with frequency and ...
shamil khal's user avatar
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Continuous wavelet transform with complex shannon wavelet [duplicate]

The complex Shannon function is defined as: It seems that Mathematica doesn't support the complex Shannon transform although it supports the real Shannon function. I need the complex Shannon function ...
Emad Ebrahimi's user avatar
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Fourier factor and Fourier transform for wavelet transform [duplicate]

To define the continuous wavelet transform in Mathematica, you need Fourier factor and Fourier transform. I don't understand how to find these two, for example, how can define these two in the haar ...
Emad Ebrahimi's user avatar
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Plot wavefronts of Laguerre-Gaussian modes

I am trying to plot wavefronts of Laguerre-Gaussian modes, and want to show the changing number of twists with the change in l values. If anyone has the code or any insights. Kindly help me about it. ...
Qubit's user avatar
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Orthonormal Wavelet functions

The wavelet function "WaveletPsi" is supposed to create an orthonormal basis of some space. Now consider e.g. the following wavelet function: ...
Daniel Huber's user avatar
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Discrete wavelet transform with complex shannon wavelet

The complex Shannon function is defined as: It seems that Mathematica doesn't support the complex Shannon transform although it supports the real Shannon function. I need the complex Shannon function ...
Emad Ebrahimi's user avatar
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79 views

Calculate wavelet coefficients with Mathematica

Let $\operatorname{rect}(x)$ be a constant function equal to 1 with support $[-1 / 2,1 / 2]$. Define a step function using the sequence as $$ f(x)=\sum_{k=1}^4 a_k \operatorname{rect}(x-k)$$ where $...
Mark's user avatar
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2 answers
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Identifying an envelope function of a wave-packet [duplicate]

I have this wavepacket, which is defined over an interval $[a,b], \ a,b\in \mathbb{R}$. Suppose the wavepacket is complex trigonometric and analytic, then how can I find, using any formula or ...
Vangsnes's user avatar
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Image Segmentation for Grid and fence of cage in Frequency Domain

I want to analysis the pattern of this kind of grid of cage, and remove them in frequency domain. The goal image is like that shown by imgFinal, it's not an ...
HyperGroups's user avatar
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One dimensional wave equation -numerical vs analitcal solution? [closed]

Recently I have been experimenting with one dimensional wave equation with Dirichlet boundary conditions. So the problem goes like this: I found this formulas in: Qiong-Gui Lin "Yet another ...
Alice211's user avatar
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Defining a new wavelet (Fibonacci wavelet)

I want to define a new wavelet (Fibonacci wavelet) in the reference. So, I read the tutorial on Wolfram Site, @Jason B. ' s answer, and also @Sektor 's answers. But I still have some problems in my ...
1_student's user avatar
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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 ...
Chris 's user avatar
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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 ...
Chris 's user avatar
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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: ...
user14717's user avatar
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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-...
DMWood's user avatar
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Integral of a Wavelet function

I ran into problems integrating a function which contains both an If condition and a Wavelet which is an ...
Ayoub's user avatar
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1 answer
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<<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 ...
Ayoub's user avatar
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2 votes
2 answers
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WaveletListPlot: Broken in 11.2?

I'm trying to create a WaveletListPlot, following the reference code exactly: ...
user14717's user avatar
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3 votes
1 answer
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Solve 1D Wave Equation

I wanna model 1D wave equation and plot it, Here is my try so far, ...
Lakshitha Wisumperuma's user avatar
1 vote
1 answer
158 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}] ...
Mutaz 's user avatar
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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: ...
wvt_beginner's user avatar
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1 answer
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Getting errors NIntegrate::nlim and NIntegrate::slwcon [closed]

Here is the modified question: First: Define phi[x_]:=Piecewise[{{1, 0 <= x < 1}}, 0] ...
Mutaz 's user avatar
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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. ...
Amira sayed's user avatar
2 votes
3 answers
172 views

Integrating a function containing a wavelet

How do I evaluate the integral c? ...
DHIRAJ UPADHYAY Dept of Mechan's user avatar
4 votes
2 answers
200 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 ...
user3318424's user avatar
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161 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 ...
user51734's user avatar
1 vote
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379 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 ...
Iconoclast's user avatar
2 votes
1 answer
220 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 ...
WhatIfWeAreWrong's user avatar
3 votes
1 answer
365 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 ...
Oscillon's user avatar
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3 votes
1 answer
170 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 ...
yode's user avatar
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1 vote
2 answers
200 views

How to detect the singular value with wavelet analysis

I have a series data data=Uncompress[ FromCharacterCode[Flatten[ImageData[Import["https://i.stack.imgur.com/ApipY.png"], "Byte"]]]]; We can show it ...
yode's user avatar
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6 votes
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423 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 ...
yode's user avatar
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1 vote
0 answers
226 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: ...
Maxim  Yalymov's user avatar
4 votes
0 answers
140 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: ...
SgrA's user avatar
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8 votes
2 answers
390 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:
M.R.'s user avatar
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2 votes
1 answer
1k 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 ...
yode's user avatar
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2 votes
0 answers
1k 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) ...
Mehmet's user avatar
  • 587
1 vote
1 answer
133 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 ...
Dan's user avatar
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2 votes
0 answers
71 views

Modified WaveletImagePlot

When performing Wavelet Transform ...
Ramya Mendharkar's user avatar
5 votes
1 answer
504 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 ...
meddy's user avatar
  • 101
5 votes
1 answer
135 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 ...
Ramya Mendharkar's user avatar
1 vote
0 answers
333 views

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

Due to ContinuousWaveletTransform[...] I can obtain information about wavelet-coefficient for example ...
Sssur's user avatar
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4 votes
3 answers
638 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 ...
Dan's user avatar
  • 233
9 votes
1 answer
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 ...
Vink's user avatar
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27 votes
3 answers
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 ...
M.R.'s user avatar
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1 vote
0 answers
132 views

Problem with DiscreteWaveletTransform for DaubechiesWavelet

I am trying to use Mathematica's wavelet transform. In preparation I entered: ...
cadri's user avatar
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1 vote
2 answers
109 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 ...
Lex Toet's user avatar
2 votes
1 answer
183 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 ...
dantopa's user avatar
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8 votes
1 answer
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 ...
M.R.'s user avatar
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