Questions tagged [wavelet]

Referring to the study of brief oscillations whose amplitude grows and decays in a finite time.

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Wavelets frame for $L^2[0,\infty)$

I need a wavelet frame for $L^2[0,\infty)$. Moreover, the wavelet should be twice differentiable and with continuous second order derivatives. Hopefully, the wavelet should have compact support (...
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Can Mallat's pyramidal algorithm be extended to non-power of 2 input sizes?

Mallat's pyramidal algorithm for the discrete wavelet transform operates on power-of-2 vector lengths. Can it be extended to work on inputs of any size without resorting to zero padding?
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Spatio-temopral wavelet analysis

Am quite new to wavelet analysis and would like some help. I am performing a spatio-temporal analysis of monthly gridded rainfall data. With PCA, I can reduce the dimension of the rainfall data into a ...
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Advantage of fractional Fourier transform over multiscale wavelet?

What could be the arguments of using fractional Fourier transform instead of multiscale wavelet for data analysis ? Optimization of the good time-frequency domain parameter? good in the sens of best ...
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47 views

How to construct Diffusion Wavelet Packets?

I understand the idea of constructing Low-pass and High-pass filters as a projection on the Numerical Range and Numerical Kernel of dyadic powers of a diffusion operator in the work Diffusion Wavelet ...
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Adjoint of the MATLAB $\tt dwt3$ (3D wavelet transform) operator

How do I compute the adjoint of MATLAB's dwt3 operator? In other words, how do I compute the adjoint of the linear operator that takes a 3D complex array ...
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65 views

Computing 3-term Connection Coefficients for Wavelets

I am trying to calculate the three-term connection coefficients $$ Λ_{l,m}^{d_1,d_2,d_3} = ∫_{-∞}^∞ φ^{(d_1)}(x) φ^{(d_2)}_l(x) φ^{(d_3)}_m(x) dx $$ for Daubechies wavelets numerically using Python. ...
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339 views

How to add a Ricker Wavelet (Mexican Hat) to a 2D/ 3D fem mesh?

I have a 2D square mesh and a 3D beam shaped mesh and I want to propagate a seismic wave in them. I am trying to simulate them using Open source FEM codes (fenics). I have left the top surface to be ...
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Computationally Feasible Wavelet transform algorithms for 1-D data with many samples

I am doing multi resolution analysis on a 1-d Dataset with large amount of samples (few millions). Currently I am experimenting with pywavelets in python but it gets incredibly intensive on ...
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38 views

Open Source Packages Implementing Continuous Wavelet and Scaling Functions

I'm looking for an open source software package that provides a fast evaluation of continuous Daubechies/Symmlet wavelet/scaling functions. GSL only has the discrete wavelets, and PyWavelets comes ...