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This paper describes the optimisation theory on which VPFIT, a non-linear least-squares program for modelling absorption spectra, is based. Particular attention is paid to precision. Voigt function derivatives have previously been…

Instrumentation and Methods for Astrophysics · Physics 2021-10-20 John K. Webb , Robert F. Carswell , Chung-Chi Lee

I present a Python package developed for fitting Voigt profiles to absorption lines. The software fits multiple components for various atomic lines simultaneously allowing parameters to be tied and fixed. Moreover, the code is able to…

Instrumentation and Methods for Astrophysics · Physics 2018-03-06 Jens-Kristian Krogager

We introduce a Bayesian approach for modeling Voigt profiles in absorption spectroscopy and its implementation in the python package, BayesVP, publicly available at https://github.com/cameronliang/BayesVP. The code fits the absorption line…

Astrophysics of Galaxies · Physics 2017-10-30 Cameron Liang , Andrey Kravtsov

Opacities of molecules in exoplanet atmospheres rely on increasingly detailed line-lists for these molecules. The line lists available today contain for many species up to several billions of lines. Computation of the spectral line profile…

Earth and Planetary Astrophysics · Physics 2017-11-08 Michiel Min

For a given {\it misfit function}, a specified optimality measure of a model, its gradient describes the manner in which one may alter properties of the system to march towards a stationary point. The adjoint method, arising from…

Solar and Stellar Astrophysics · Physics 2015-05-28 Shravan Hanasoge , Aaron Birch , Laurent Gizon , Jeroen Tromp

A new sampling methodology based on incomplete cosine expansion series is presented as an alternative to the traditional sinc function approach. Numerical integration shows that this methodology is efficient and practical. Applying the…

Numerical Analysis · Mathematics 2015-03-24 S. M. Abrarov , B. M. Quine

A new and automated method is presented for the analysis of high-resolution absorption spectra. Three established numerical methods are unified into one "artificial intelligence" process: a genetic algorithm (GVPFIT); non-linear…

Instrumentation and Methods for Astrophysics · Physics 2017-02-01 Matthew B. Bainbridge , John K. Webb

We report an exact analytical solution of so-called positron diffusion trapping model. This model have been widely used for the treatment of the experimental data for defect profiling of the adjoin surface layer using the variable energy…

Materials Science · Physics 2015-06-16 V. A. Stephanovich , J. Dryzek

Exploring the possibility that fundamental constants of Nature might vary temporally or spatially constitutes one of the key science drivers for the European Southern Observatory's ESPRESSO spectrograph on the VLT and for the HIRES…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-21 Chung-Chi Lee , John K. Webb , R. F. Carswell , Dinko Milaković

The Voigt profile - a convolution of a Gaussian and a Lorentzian - accurately describes the absorption lines of atomic and molecular gases at low probe powers. Fitting such to experimental spectra yields both the Lorentzian natural…

Atomic Physics · Physics 2015-06-04 Thomas M. Stace , Gar-Wing Truong , James Anstie , Eric F. May , Andre N. Luiten

The rational function approximation provides a natural and interpretable representation of response functions such as the many-body spectral functions. We apply the Vector Fitting (VFIT) algorithm to fit a variety of spectral functions…

Statistical Mechanics · Physics 2024-02-20 Shubhang Goswami , Kipton Barros , Matthew R. Carbone

This work presents a method of computing Voigt functions and their derivatives, to high accuracy, on a uniform grid. It is based on an adaptation of Fourier-transform based convolution. The relative error of the result decreases as the…

Data Analysis, Statistics and Probability · Physics 2007-05-23 Marcus H. Mendenhall

Evaluation of the Voigt function, a convolution of a Lorentzian and a Gaussian profile, is essential in various fields such as spectroscopy, atmospheric science, and astrophysics. Efficient computation of the function is crucial, especially…

Instrumentation and Methods for Astrophysics · Physics 2024-11-05 Mofreh R. Zaghloul , Jacques Le Bourlot

We propose and demonstrate an alternating Fourier and image domain filtering approach for feature extraction as an efficient alternative to build a vision backbone without using the computationally intensive attention. The performance among…

Computer Vision and Pattern Recognition · Computer Science 2024-09-27 Yunling Zheng , Zeyi Xu , Fanghui Xue , Biao Yang , Jiancheng Lyu , Shuai Zhang , Yingyong Qi , Jack Xin

We introduce Adjoint Sampling, a highly scalable and efficient algorithm for learning diffusion processes that sample from unnormalized densities, or energy functions. It is the first on-policy approach that allows significantly more…

This paper describes the implementation and performance of adiabatic absorbing layers in an FFT-accelerated volume integral equation (VIE) method for simulating truncated nanophotonics structures. At the truncation sites, we place absorbing…

Computational Physics · Physics 2018-08-15 Alexandra Tambova , Samuel P. Groth , Jacob K. White , Athanasios G. Polimeridis

Additive models can be used for interpretable machine learning for their clarity and simplicity. However, In the classical models for high-order data, the vectorization operation disrupts the data structure, which may lead to degenerated…

Machine Learning · Computer Science 2024-06-06 Yang Chen , Ce Zhu , Jiani Liu , Yipeng Liu

Bayesian optimization in large unstructured discrete spaces is often hindered by the computational cost of maximizing acquisition functions due to the absence of gradients. We propose a scalable alternative based on Thompson sampling that…

Machine Learning · Computer Science 2026-03-02 Nicolas Menet , Aleksandar Terzić , Michael Hersche , Andreas Krause , Abbas Rahimi

Optimization of strongly non-linear tightly coupled feeds attached to antennas is a challenging problem from a purely computational perspective. One can imagine that an optimization would (a) need to be in the time domain, and (b) has to be…

Optimization and Control · Mathematics 2023-04-25 Sean F. DePalma , Omkar H. Ramachandran , Leo C. Kempel , B. Shanker

Algorithm-Based Fault Tolerance (ABFT) is widely adopted to detect silent data corruptions (SDCs) in matrix multiplication, a cornerstone operation in deep learning systems. However, existing threshold determination methods face critical…

Machine Learning · Computer Science 2026-02-10 Yiheng Gao , Qin Hua , Zizhong Chen
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