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Fast spherical harmonic transforms

WebThe spherical harmonic (SH) expansion technique maps a variable on a spherical surface to its representation in the SH function space in terms of SH expansion coefficients. This technique, also known as the spectral transform method, has been employed in global atmospheric modeling efforts (Williamson, 2007 ), including numerical weather ... WebJul 1, 2010 · We demonstrate a fast spin-s spherical harmonic transform algorithm, which is flexible and exact for band-limited functions. In contrast to previous work, where spin …

High resolution spherical and ellipsoidal harmonic expansions by Fast …

WebMar 19, 2014 · Nevertheless, we achieve high accuracy even for very large band-limits. For our optimal-dimensionality sampling scheme, we develop a fast and accurate algorithm to compute the spherical harmonic transform (and inverse), with computational complexity comparable with existing schemes in practice. metabase itec https://coyodywoodcraft.com

WAVEMOTH–FAST SPHERICAL HARMONIC TRANSFORMS BY …

WebOct 18, 2024 · This method can be used to reconstruct band limited spherical harmonic or Wigner D-function series (spherical harmonic series are a special case) with sparse … WebAug 13, 2014 · High resolution transformations between regular geophysical data and harmonic model coefficients can be most efficiently computed by Fast Fourier Transform (FFT). However, a prerequisite is that the data grids are given in … WebNov 1, 1999 · 1 Introduction. Many geophysical problems involve spherical geometry. Some can be described as data processing while others involve the solution of partial differential equations in spherical coordinates; in both cases it is useful to transform between a spatial representation and a set of spherical harmonic coefficients. how tall is willie cauley stein

An Optimal-Dimensionality Sampling Scheme on the Sphere With Fast …

Category:arXiv:1110.4874v2 [astro-ph.IM] 12 Jan 2012

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Fast spherical harmonic transforms

An Optimal-Dimensionality Sampling Scheme on the Sphere With …

WebJul 31, 2024 · 4 fast vector spherical harmonic transforms In Subsections 4.1 and 4.2 below, we prov e two theorems to represent the vector spherical harmonic transforms by scalar spherical harmonics and Clebsch ... WebThe SSHT code provides functionality to perform fast and exact spin spherical harmonic transforms based on the sampling theorem on the sphere derived in McEwen & …

Fast spherical harmonic transforms

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WebJan 21, 2013 · The fast Fourier transform (FFT) should be used for this part, as it improves accuracy and speed. SHTns uses the FFTW library [ Frigo & Johnson, 2005 ], a portable, … WebWe develop a sampling scheme on the sphere that permits accurate computation of the spherical harmonic transform and its inverse for signals band-limited at using only samples. We obtain the optimal number of samples…

WebM.P. Mohlenkamp, A fast transform for spherical harmonics, J. Fourier Anal. Appl. 5 (2/3) (1999) 159–184. Google Scholar S. Moore, Efficient stabilization methods for fast polynomial transforms, Ph.D. thesis, Department of Mathematics and Computer Science, Dartmouth College (1994). WebJan 17, 2024 · It implements the novel spherical harmonic transform (NSHT) of a band-limited signal using the optimal number of samples. ... Z. Khalid, R. A. Kennedy and J. D. McEwen, “An Optimal-Dimensionality Sampling Scheme on the Sphere for Fast Spherical Harmonic Transforms,” IEEE Trans. Signal Process., vol. 62, no. 17, pp. 4597-4610, …

WebThe spherical harmonic transform (SHT) is the spher-ical analog of the Fourier transform, and is an essential tool for data analysis and simulation on the sphere. A scalar field f(θ,φ) on the unit sphere can be expressed as a weighted sum of the spherical harmonic basis functions Yℓm(θ,φ), f(θ,φ) = X∞ ℓ=0 Xℓ m=−ℓ aℓmYℓm ... WebIn physics and mathematics, the Fourier transform (FT) is a transform that converts a function into a form that describes the frequencies present in the original function. The output of the transform is a complex-valued function of frequency.The term Fourier transform refers to both this complex-valued function and the mathematical …

WebThe spectral synthesis and analysis algorithms using fast Fourier transforms and Legendre transforms with the associated Legendre functions are presented in detail. A set of methods associated with a spectral_field class provides spectral approximation to the differential operators ∇ ⋯, ∇ ×, ∇, and ∇ 2 in spherical geometry.

http://sun.stanford.edu/~tplarson/NoiseModel.pdf metabase or supersetWebMar 1, 2005 · The fast spherical harmonic transform algorithm proposed by Suda and Takami is evaluated in the solutions of the shallow water equation test set defined by … metabase machine learningWebApr 24, 2024 · Mathematica's implementation of the Fast Fourier Transform is, naturally, much faster than computing the discrete transform yourself using Sum. The analog of the Fourier transform of a function f … how tall is willie nelson and weightWebJun 3, 2016 · SHTns is a high performance library for Spherical Harmonic Transform written in C, aimed at numerical simulation (fluid flows, mhd, ...) in spherical geometries. … metabase pricingWebFeb 15, 2012 · The spherical harmonic transform (SHT) is the spherical analog of the Fourier transform and is an essential tool for data analysis and simulation on the … how tall is william wallaceWebSpherical harmonic expansions are a well-understood and widely used tool of applied math- ematics; they are encountered, inter alia, in weather and climate modeling, in … how tall is william mapotherWebOct 1, 2013 · This article describes the implementation of a practical fast spherical harmonics transform into the Integrated Forecast System (IFS) at ECMWF. Details of … metabase optional variable