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Astrophysics Source Code Library

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Searching for codes credited to 'S de Souza, Rafael'

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Found 8 codes.

[ascl:2507.023] Capivara: Scalable spectral-based segmentation package
Capivara implements a spectral-based segmentation method for Integral Field Unit (IFU) data cubes. The code uses hierarchical clustering in the spectral domain, grouping similar spectra to improve the signal-to-noise ratio without compromising astrophysical similarity among regions, and leverages advanced matrix operations via torch for GPU acceleration.
[ascl:2404.005] GalMOSS: GPU-accelerated galaxy surface brightness fitting via gradient descent
GalMOSS performs two-dimensional fitting of galaxy profiles. This Python-based, Torch-powered tool seamlessly enables GPU parallelization and meets the high computational demands of large-scale galaxy surveys. It incorporates widely used profiles such as the Sérsic, Exponential disk, Ferrer, King, Gaussian, and Moffat profiles, and allows for the easy integration of more complex models. Tested on over 8,000 galaxies from the Sloan Digital Sky Survey (SDSS) g-band with a single NVIDIA A100 GPU, GalMOSS completed classical Sérsic profile fitting in about 10 minutes. Benchmark tests show that GalMOSS achieves computational speeds that are significantly faster than those of default implementations.
[ascl:2306.013] SCONCE-SCMS: Spherical and conic cosmic web finders with extended SCMS algorithms
SCONCE-SCMS detects cosmic web structures, primarily cosmic filaments and the associated cosmic nodes, from a collection of discrete observations with the extended subspace constrained mean shift (SCMS) algorithms on the unit (hyper)sphere (in most cases, the 2D (RA,DEC) celestial sphere), and the directional-linear products space (most commonly, the 3D (RA,DEC,redshift) light cone).

The subspace constrained mean shift (SCMS) algorithm is a gradient ascent typed method dealing with the estimation of local principal curves, more widely known as density ridges. The one-dimensional density ridge traces over the curves where observational data are highly concentrated and thus serves as a natural model for cosmic filaments in our Universe. Modeling cosmic filaments as density ridges enables efficient estimation by the kernel density estimator (KDE) and the subsequent SCMS algorithm in a statistically consistent way. While the standard SCMS algorithm can identify the density ridges in any "flat" Euclidean space, it exhibits large bias in estimating the density ridges on the data space with a non-linear curvature. The extended SCMS algorithms used in SCONCE-SCMS are adaptive to the spherical and conic geometries and resolve the estimation bias of the standard SCMS algorithm on a 2D (RA,DEC) celestial sphere or 3D (RA,DEC,redshift) light cone.
[ascl:2208.025] Yonder: Data denoising and reconstruction
YONDER uses singular value decomposition to perform low-rank data denoising and reconstruction. It takes a tabular data matrix and an error matrix as input and returns a denoised version of the original dataset as output. The approach enables a more accurate data analysis in the presence of uncertainties. Consequently, this package can be used as a simple toolbox to perform astronomical data cleaning.
[ascl:2208.002] qrpca: QR-based Principal Components Analysis
qrpca uses QR-decomposition for fast principal component analysis. The software is particularly suited for large dimensional matrices. It makes use of torch for internal matrix computations and enables GPU acceleration, when available. Written in both R and python languages, qrpca provides functionalities similar to the prcomp (R) and sklearn (python) packages.
[ascl:1512.009] DRACULA: Dimensionality Reduction And Clustering for Unsupervised Learning in Astronomy
DRACULA classifies objects using dimensionality reduction and clustering. The code has an easy interface and can be applied to separate several types of objects. It is based on tools developed in scikit-learn, with some usage requiring also the H2O package.
[ascl:1503.006] AMADA: Analysis of Multidimensional Astronomical DAtasets
AMADA allows an iterative exploration and information retrieval of high-dimensional data sets. This is done by performing a hierarchical clustering analysis for different choices of correlation matrices and by doing a principal components analysis in the original data. Additionally, AMADA provides a set of modern visualization data-mining diagnostics. The user can switch between them using the different tabs.
[ascl:1408.018] CosmoPhotoz: Photometric redshift estimation using generalized linear models
CosmoPhotoz determines photometric redshifts from galaxies utilizing their magnitudes. The method uses generalized linear models which reproduce the physical aspects of the output distribution. The code can adopt gamma or inverse gaussian families, either from a frequentist or a Bayesian perspective. A set of publicly available libraries and a web application are available. This software allows users to apply a set of GLMs to their own photometric catalogs and generates publication quality plots with no involvement from the user. The code additionally provides a Shiny application providing a simple user interface.