Results 1651-1700 of 3572 (3481 ASCL, 91 submitted)

[ascl:1403.019]
KINEMETRY: Analysis of 2D maps of kinematic moments of LOSVD

KINEMETRY, written in IDL, analyzes 2D maps of the moments of the line-of-sight velocity distribution (LOSVD). It generalizes the surface photometry to all moments of the LOSVD. It performs harmonic expansion of 2D maps of observed moments (surface brightness, velocity, velocity dispersion, h3, h4, etc.) along the best fitting ellipses (either fixed or free to change along the radii) to robustly quantify maps of the LOSVD moments, describe trends in structures, and detect morphological and kinematic sub-components.

[ascl:2008.001]
kinesis: Kinematic modeling of clusters

Kinesis fits the internal kinematics of a star cluster with astrometry and (incomplete) radial velocity data of its members. In the most general model, the stars can be a mixture of background (contamination) and the cluster, for which the (3,3) velocity dispersion matrix and velocity gradient (*i.e.*, dv_x/dx and dv_y/dx) are included. There are also simpler versions of the most general model and utilities to generate mock clusters and mock observations.

[ascl:2006.003]
KinMS: Three-dimensional kinematic modeling of arbitrary gas distributions

The KinMS (KINematic Molecular Simulation) package simulates observations of arbitrary molecular/atomic cold gas distributions from interferometers and line observations from integral field units. This modeling tool is optimized for situations where one has analytic forms for *e.g.* the rotation curve and/or surface brightness profiles (and may want to fit the parameters of these parametric models). It can, however, also be used as a tilted-ring modelling code. The routines are flexible and have been used in various different applications, including investigating the kinematics of molecular gas in early-type galaxies and determining supermassive black-hole masses from CO interferometric observations. They are also useful for creating mock observations from hydrodynamic simulations, and input data-cubes for further simulation in, for example, CASA's (ascl:1107.013) sim_observe tool. Interactive Data Language (IDL) and Python versions of the code are available.

[ascl:1401.001]
Kirin: N-body simulation library for GPUs

The use of graphics processing units offers an attractive alternative to specialized hardware, like GRAPE. The Kirin library mimics the behavior of the GRAPE hardware and uses the GPU to execute the force calculations. It is compatible with the GRAPE6 library; existing code that uses the GRAPE6 library can be recompiled and relinked to use the GPU equivalents of the GRAPE6 functions. All functions in the GRAPE6 library have an equivalent GPU implementation. Kirin can be used for direct N-body simulations as well as for treecodes; it can be run with shared-time steps or with block time-steps and allows non-softened potentials. As Kirin makes use of CUDA, it works only on NVIDIA GPUs.

[submitted]
Kliko - The Scientific Compute Container Format

We present Kliko, a Docker based container specification for running one or multiple related compute jobs. The key concepts of Kliko is the encapsulation of data processing software into a container and the formalisation of the input, output and task parameters. Formalisation is realised by bundling a container with a Kliko file, which describes the IO and task parameters. This Kliko container can then be opened and run by a Kliko runner. The Kliko runner will parse the Kliko definition and gather the values for these parameters, for example by requesting user input or pre defined values in a script. Parameters can be various primitive types, for example float, int or the path to a file. This paper will also discuss the implementation of a support library named Kliko which can be used to create Kliko containers, parse Kliko definitions, chain Kliko containers in workflows using, for example, Luigi a workflow manager. The Kliko library can be used inside the container interact with the Kliko runner. Finally this paper will discuss two reference implementations based on Kliko: RODRIGUES, a web based Kliko container schedular and output visualiser specifically for astronomical data, and VerMeerKAT, a multi container workflow data reduction pipeline which is being used as a prototype pipeline for the commisioning of the MeerKAT radio telescope.

[ascl:2008.003]
KLLR: Kernel Localized Linear Regression

Farahi, Arya; Evrard, August E.; McCarthy, Ian; Barnes, David J.; Kay, Scott T.; Anbajagane, Dhayaa; Dolag, Klaus; McCarthy, Ian G.; Nelson, Dylan; Pillepich, Annalisa

KLLR (Kernel Localized Linear Regression) generates estimates of conditional statistics in terms of the local slope, normalization, and covariance. This method provides a more nuanced description of population statistics appropriate for very large samples with non-linear trends. The code uses a bootstrap re-sampling technique to estimate the uncertainties and also provides tools to seamlessly generate visualizations of the model parameters.

[ascl:1606.012]
KMDWARFPARAM: Parameters estimator for K and M dwarf stars

KMDWARFPARAM estimates the physical parameters of a star with mass M < 0.8 M_sun given one or more observational constraints. The code runs a Markov-Chain Monte Carlo procedure to estimate the parameter values and their uncertainties.

[ascl:2106.001]
KOBE: Kepler Observes Bern Exoplanets

KOBE (Kepler Observes Bern Exoplanets) adds the geometrical limitations and the physical detection biases of the transit method to a given population of theoretical planets. In addition, it also adds the completeness and reliability of a transit survey.

[ascl:2004.010]
kombine: Kernel-density-based parallel ensemble sampler

kombine is an ensemble sampler built for efficiently exploring multimodal distributions. By using estimates of ensemble’s instantaneous distribution as a proposal, it achieves very fast burnin, followed by sampling with very short autocorrelation times.

[ascl:2211.016]
Korg: 1D local thermodynamic equilibrium stellar spectral synthesis

Korg computes stellar spectra from 1D model atmospheres and linelists assuming local thermodynamic equilibrium and implements both plane-parallel and spherical radiative transfer. The code is generally faster than other codes, and is compatible with automatic differentiation libraries and easily extensible, making it ideal for statistical inference and parameter estimation applied to large data sets.

[ascl:1504.013]
kozai: Hierarchical triple systems evolution

The kozai Python package evolves hierarchical triple systems in the secular approximation. As its name implies, the kozai package is useful for studying Kozai-Lidov oscillations. The kozai package can represent and evolve hierarchical triples using either the Delaunay orbital elements or the angular momentum and eccentricity vectors. kozai contains functions to calculate the period of Kozai-Lidov oscillations and the maximum eccentricity reached; it also contains a module to study octupole order effects by averaging over individual Kozai-Lidov oscillations.

[ascl:1807.027]
kplr: Tools for working with Kepler data using Python

kplr provides a lightweight Pythonic interface to the catalog of planet candidates (Kepler Objects of Interest [KOIs]) in the NASA Exoplanet Archive and the data stored in the Barbara A. Mikulski Archive for Space Telescopes (MAST). kplr automatically supports loading Kepler data using pyfits (ascl:1207.009) and supports two types of data: light curves and target pixel files.

[ascl:1609.003]
Kranc: Cactus modules from Mathematica equations

Kranc turns a tensorial description of a time dependent partial differential equation into a module for the Cactus Computational Toolkit (ascl:1102.013). This Mathematica application takes a simple continuum description of a problem and generates highly efficient and portable code, and can be used both for rapid prototyping of evolution systems and for high performance supercomputing.

[ascl:1402.011]
KROME: Chemistry package for astrophysical simulations

Grassi, Tommaso; Bovino, Stefano; Prieto, Joaquín; Seifried, Daniel; Simoncini, Eugenio; Gianturco, Francesco; Schleicher, Dominik

KROME, given a chemical network (in CSV format), automatically generates all the routines needed to solve the kinetics of the system modeled as a system of coupled Ordinary Differential Equations. It provides a large set of physical processes connected to chemistry, including photochemistry, cooling, heating, dust treatment, and reverse kinetics. KROME is flexible and can be used for a wide range of astrophysical simulations. The package contains a network for primordial chemistry, a small metal network appropriate for the modeling of low metallicities environments, a detailed network for the modeling of molecular clouds, and a network for planetary atmospheres as well as a framework for the modelling of the dust grain population.

[ascl:1505.004]
KS Integration: Kelvin-Stokes integration

KS Intergration solves for mutual photometric effects produced by planets and spots allowing for analysis of planetary occultations of spots and spots regions. It proceeds by identifying integrable and non integrable arcs on the objects profiles and analytically calculates the solution exploiting the power of Kelvin-Stokes theorem. It provides the solution up to the second degree of the limb darkening law.

[ascl:1804.026]
KSTAT: KD-tree Statistics Package

KSTAT calculates the 2 and 3-point correlation functions in discreet point data. These include the two-point correlation function in 2 and 3-dimensions, the anisotripic 2PCF decomposed in either sigma-pi or Kazin's dist. mu projection. The 3-point correlation function can also work in anisotropic coordinates. The code is based on kd-tree structures and is parallelized using a mixture of MPI and OpenMP.

[ascl:1807.028]
ktransit: Exoplanet transit modeling tool in python

The routines in ktransit create and fit a transiting planet model. The underlying model is a Fortran implementation of the Mandel & Agol (2002) limb darkened transit model. The code calculates a full orbital model and eccentricity can be allowed to vary; radial velocity data can also be calculated via the model and included in the fit.

[ascl:1407.011]
kungifu: Calibration and reduction of fiber-fed IFU astronomical spectroscopy

kungifu is a set of IDL software routines designed for the calibration and reduction of fiber-fed integral-field unit (IFU) astronomical spectroscopy. These routines can perform optimal extraction of IFU data and allow relative and absolute wavelength calibration to within a few hundredths of a pixel (for unbinned data) across 1200-2000 fibers. kungifu does nearly Poisson-limited sky subtraction, even in the I band, and can rebin in wavelength. The Princeton IDLUTILS and IDLSPEC2D packages must be installed for kungifu to run.

[ascl:2311.004]
KvW: Modified Kwee–Van Woerden method for eclipse minimum timing with reliable error estimates

The KvW code applies the Kwee Van Woerden (KvW) method for eclipse or transit minimum timing, with an improved error calculation that avoids underestimated errors in minimum times that may appear in the original method. This is particularly the case for low-noise eclipse or transit lightcurves from space or from modern ground instrumentation. The code requires an input light curve of near-equidistant points that contains only the eclipse, without any off-eclipse points, and is available in python and IDL. Both implementaitons return an eclipse minimum time with its error and provide optional text output and plots, as well as several levels of debug information.

[ascl:1507.004]
L-PICOLA: Fast dark matter simulation code

L-PICOLA generates and evolves a set of initial conditions into a dark matter field and can include primordial non-Gaussianity in the simulation and simulate the past lightcone at run-time, with optional replication of the simulation volume. It is a fast, distributed-memory, planar-parallel code. L-PICOLA is extremely useful for both current and next generation large-scale structure surveys.

[ascl:1207.005]
L.A.Cosmic: Laplacian Cosmic Ray Identification

Conventional algorithms for rejecting cosmic rays in single CCD exposures rely on the contrast between cosmic rays and their surroundings and may produce erroneous results if the point-spread function is smaller than the largest cosmic rays. This code uses a robust algorithm for cosmic-ray rejection, based on a variation of Laplacian edge detection. The algorithm identifies cosmic rays of arbitrary shapes and sizes by the sharpness of their edges and reliably discriminates between poorly sampled point sources and cosmic rays. Examples of its performance are given for spectroscopic and imaging data, including Hubble Space Telescope Wide Field Planetary Camera 2 images, in the code paper.

[ascl:2112.024]
l1p: Python implementation of the l1 periodogram

The l1 periodogram searches for periodicities in unevenly sampled time series. It can be used similarly as a Lomb-Scargle periodogram, and retrieves a figure which has a similar aspect but has fewer peaks due to aliasing. It is primarily designed for the search of exoplanets in radial velocity data, but can be also used for other purposes. The principle of the algorithm is to search for a representation of the input signal as a sum of a small number of sinusoidal components, that is a representation which is sparse in the frequency domain. Here, "small number" means small compared to the number of observations.

[ascl:1601.011]
LACEwING: LocAting Constituent mEmbers In Nearby Groups

LACEwING (LocAting Constituent mEmbers In Nearby Groups) uses the kinematics (positions and motions) of stars to determine if they are members of one of 10 nearby young moving groups or 4 nearby open clusters within 100 parsecs. It is written for Python 2.7 and depends upon Numpy, Scipy, and Astropy (ascl:1304.002) modules. LACEwING can be used as a stand-alone code or as a module in other code. Additional python programs are present in the repository for the purpose of recalibrating the code and producing other analyses, including a traceback analysis.

[ascl:2408.007]
LADDER: Learning Algorithm for Deep Distance Estimation and Reconstruction

LADDER (Learning Algorithm for Deep Distance Estimation and Reconstruction) reconstructs the “cosmic distance ladder” by analyzing sequential cosmological data; it can also be applied to other sequential datasets with associated covariance information. It uses the apparent magnitude data from the Pantheon Type Ia supernovae compilation, fully incorporating covariance information to accurately predict mean values and uncertainties. It offers model-independent consistency checks for datasets such as Baryon Acoustic Oscillations (BAO) and can calibrate high-redshift datasets such as Gamma Ray Bursts (GRBs) without assuming any underlying cosmological model. Additionally, LADDER serves as a model-independent mock catalog generator for forecast-based cosmological studies.

[ascl:2104.008]
LaFuLi: NASA Langley Fu-Liou radiative transfer code

The NASA Langley Fu-Liou radiative transfer code (also known as Ed4 LaRC Fu-Liou) computes broadband solar shortwave and thermal long wave profiles of down-welling and up-welling flux accounting for gas absorption by H2O, CO2, O3, O2, CH4, N2O and CFCs and absorption and scattering by clouds and aerosols. Longwave has options of a four-stream or 2/4 stream solver, while shortwave has options for two-stream, four-stream or Gamma weighted two-stream (GWTSA) which treats the inhomogeniety of cloud optical depth. A delta-Eddington approximation is used to treat the forward scattering peak. Water cloud properties are based on Mie calculations and ice cloud properties or the ice particle aspect ratio. Aerosol properties are given for 25 types.

[ascl:2012.021]
LALSuite: LIGO Scientific Collaboration Algorithm Library Suite

LALSuite contains numerous gravitational wave analysis libraries. Written primarily in C, the libraries include math and signal analysis packages such as for vector manipulation, FFT, statistics, time-domain filtering, and numerical and signal injection routines. The libraries also include date and time and datatype factory routines, in addition to general and support tools and a variety of Python packages. Also included are packages for gravitational waveform and noise generation, burst gravitational wave data analysis, inspiral and ringdown CBC gravitational wave data analysis, pulsar and continuous wave gravitational wave data analysis, and Bayesian inference data analysis. Various wrappers and other tools are also included.

[ascl:1604.003]
LAMBDAR: Lambda Adaptive Multi-Band Deblending Algorithm in R

LAMBDAR measures galaxy fluxes from an arbitrary FITS image, covering an arbitrary photometric wave-band, when provided all parameters needed to construct galactic apertures at the required locations for multi-band matched aperture galactic photometry. Through sophisticated matched aperture photometry, the package develops robust Spectral Energy Distributions (SEDs) and accurately establishes the physical properties of galactic objects. LAMBDAR was based on a package detailed in Bourne et al. (2012) that determined galactic fluxes in low resolution Herschel images.

[ascl:1010.077]
LAMDA: Leiden Atomic and Molecular Database

LAMDA provides users of radiative transfer codes with the basic atomic and molecular data needed for the excitation calculation. Line data of a number of astrophysically interesting species are summarized, including energy levels, statistical weights, Einstein A-coefficients and collisional rate coefficients. Available collisional data from quantum chemical calculations and experiments are in some cases extrapolated to higher energies. Currently the database contains atomic data for 3 species and molecular data for 28 different species. In addition, several isotopomers and deuterated versions are available. This database should form an important tool in analyzing observations from current and future infrared and (sub)millimetre telescopes. Databases such as these rely heavily on the efforts by the chemical physics community to provide the relevant atomic and molecular data. Further efforts in this direction are strongly encouraged so that the current extrapolations of collisional rate coefficients can be replaced by actual calculations in future releases.

RADEX (ascl:1010.075), a computer program for performing statistical equilibrium calculations, is made publicly available as part of the data base.

[ascl:1409.003]
LANL*: Radiation belt drift shell modeling

LANL* calculates the magnetic drift invariant L*, used for modeling radiation belt dynamics and other space weather applications, six orders of magnitude (~ one million times) faster than convectional approaches that require global numerical field lines tracing and integration. It is based on a modern machine learning technique (feed-forward artificial neural network) by supervising a large data pool obtained from the IRBEM library, which is the traditional source for numerically calculating the L* values. The pool consists of about 100,000 samples randomly distributed within the magnetosphere (r: [1.03, 11.5] Re) and within a whole solar cycle from 1/1/1994 to 1/1/2005. There are seven LANL* models, each corresponding to its underlying magnetic field configuration that is used to create the data sample pool. This model has applications to real-time radiation belt forecasting, analysis of data sets involving tens of satellite-years of observations, and other problems in space weather.

[ascl:2104.020]
LAPACK: Linear Algebra PACKage

LAPACK provides routines for solving systems of simultaneous linear equations, least-squares solutions of linear systems of equations, eigenvalue problems, and singular value problems. The associated matrix factorizations (LU, Cholesky, QR, SVD, Schur, generalized Schur) are also provided, as are related computations such as reordering of the Schur factorizations and estimating condition numbers. Dense and banded matrices are handled, but not general sparse matrices. In all areas, similar functionality is provided for real and complex matrices, in both single and double precision. The list of LAPACK Contributors is available online.

[ascl:1703.001]
Larch: X-ray Analysis for Synchrotron Applications using Python

Larch is an open-source library and toolkit written in Python for processing and analyzing X-ray spectroscopic data. The primary emphasis is on X-ray spectroscopic and scattering data collected at modern synchrotron sources. Larch provides a wide selection of general-purpose processing, analysis, and visualization tools for processing X-ray data; its related target application areas include X-ray absorption fine structure (XAFS), micro-X-ray fluorescence (XRF) maps, quantitative X-ray fluorescence, X-ray absorption near edge spectroscopy (XANES), and X-ray standing waves and surface scattering. Larch provides a complete set of XAFS Analysis tools and has support for visualizing and analyzing XRF maps and spectra, and additional tools for X-ray spectral analysis, data handling, and general-purpose data modeling.

[ascl:1208.015]
Lare3d: Lagrangian-Eulerian remap scheme for MHD

Lare3d is a Lagrangian-remap code for solving the non-linear MHD equations in three spatial dimensions.

[ascl:1806.021]
LASR: Linear Algorithm for Significance Reduction

LASR removes stellar variability in the light curves of δ-Scuti and similar stars. It subtracts oscillations from a time series by minimizing their statistical significance in frequency space.

[ascl:2010.006]
LaSSI: Large-Scale Structure Information

LaSSI produces forecasts for the LSST 3x2 point functions analysis, or the LSSTxCMB S4 and LSSTxSO 6x2 point functions analyses using a Fisher matrix. It computes the auto and cross correlations of galaxy number density, galaxy shear and CMB lensing convergence. The software includes the effect of Gaussian and outlier photo-z errors, shear multiplicative bias, linear galaxy bias, and extensions to ΛCDM.

[ascl:2306.033]
lasso_spectra: Predict properties from galaxy spectra using Lasso regression

Jensen, Hannes; Zackrisson, Erik; Pelckmans, Kristiaan; Binggeli, Christian; Ausmees, Kristiina; Lundholm, Ulrika

lasso_spectra fits Lasso regression models to data, specifically galaxy spectra. It contains two classes for performing the actual model fitting. GeneralizedLasso is a tensorflow implementation of Lasso regression, which includes the ability to use link functions. SKLasso is a wrapper around the scikit-learn Lasso implementation intended to give the same syntax as GeneralizedLasso. It is much faster and more reliable, but does not support generalized linear models.

[ascl:2205.006]
LATTE: Lightcurve Analysis Tool for Transiting Exoplanet

LATTE identifies, vets and characterizes signals in TESS lightcurves to weed out instrumental and astrophysical false positives. The program performs a fast in-depth analysis of targets that have already been identified as promising candidates by the main TESS pipelines or via alternative methods such as citizen science. The code automatically downloads the data products for any chosen TIC ID (short or long cadence TESS data) and produces a number of diagnostic plots that are compiled in a concise report.

[ascl:1911.015]
LATTICEEASY: Lattice simulator for evolving interacting scalar fields in an expanding universe

LATTICEEASY creates lattice simulations of the evolution of interacting scalar fields in an expanding universe. The program can do runs with different parameters and new models can be easily introduced for evaluation. Simulations can be done in one, two, or three dimensions by resetting a single variable. Mathematica notebooks for plotting the output and a range of models are also available for download; a parallel processing version of LATTICEEASY called CLUSTEREASY (ascl:1911.016) is also available.

[ascl:1202.011]
Lattimer-Swesty Equation of State Code

The Lattimer-Swesty Equation of State code is rapid enough to use directly in hydrodynamical simulations such as stellar collapse calculations. It contains an adjustable nuclear force that accurately models both potential and mean-field interactions and allows for the input of various nuclear parameters, including the bulk incompressibility parameter, the bulk and surface symmetry energies, the symmetric matter surface tension, and the nucleon effective masses. This permits parametric studies of the equation of state in astrophysical situations. The equation of state is modeled after the Lattimer, Lamb, Pethick, and Ravenhall (LLPR) compressible liquid drop model for nuclei, and includes the effects of interactions and degeneracy of the nucleon outside nuclei.

[ascl:2210.018]
LavAtmos: Gas-melt equilibrium calculations for a given temperature and melt composition

LavAtmos performs gas-melt equilibrium calculations for a given temperature and melt composition. The thermodynamics of the melt are modeled by the MELTS code as presented in the Thermoengine package (ascl:2208.006). In combination with atmospheric chemistry codes, LavAtmos enables the characterization of interior compositions through atmospheric signatures.

[ascl:2301.014]
LBL: Line-by-line velocity measurements

Artigau, Étienne; Cadieux, Charles; Cook, Neil J.; Doyon, René; Vandal, Thomas; Donati, Jean-François; Moutou, Claire; Delfosse, Xavier; Fouqué, Pascal; Martioli, Eder; Bouchy, François; Parsons, Jasmine; Carmona, Andres; Dumusque, Xavier; Astudillo-Defru, Nicola; Bonfils, Xavier; Mignon, Lucille

LBL derives velocity measurements from high-resolution (R>50 000) datasets by accounting for outliers in the spectra data. It is tailored for fiber-fed multi-order spectrographs, both in optical and near-infrared (up to 2.5µm) domains. The domain is split into individual units (lines) and the velocity and its associated uncertainty are measured within each line and combined through a mixture model to allow for the presence of spurious values. In addition to the velocity, other quantities are also derived, the most important being a value (dW) that can be understood (for a Gaussian line) as a change in the line FWHM. These values provide useful stellar activity indicators. LBL works on data from a variety of instruments, including SPIRou, NIRPS, HARPS, and ESPRESSO. The code's output is an rdb table that can be uploaded to the online DACE pRV analysis tool.

[ascl:1405.001]
LBLRTM: Line-By-Line Radiative Transfer Model

LBLRTM (Line-By-Line Radiative Transfer Model) is an accurate line-by-line model that is efficient and highly flexible. LBLRTM attributes provide spectral radiance calculations with accuracies consistent with the measurements against which they are validated and with computational times that greatly facilitate the application of the line-by-line approach to current radiative transfer applications. LBLRTM has been extensively validated against atmospheric radiance spectra from the ultra-violet to the sub-millimeter.

LBLRTM's heritage is in FASCODE [Clough et al., 1981, 1992].

[ascl:1708.017]
LCC: Light Curves Classifier

Light Curves Classifier uses data mining and machine learning to obtain and classify desired objects. This task can be accomplished by attributes of light curves or any time series, including shapes, histograms, or variograms, or by other available information about the inspected objects, such as color indices, temperatures, and abundances. After specifying features which describe the objects to be searched, the software trains on a given training sample, and can then be used for unsupervised clustering for visualizing the natural separation of the sample. The package can be also used for automatic tuning parameters of used methods (for example, number of hidden neurons or binning ratio).

Trained classifiers can be used for filtering outputs from astronomical databases or data stored locally. The Light Curve Classifier can also be used for simple downloading of light curves and all available information of queried stars. It natively can connect to OgleII, OgleIII, ASAS, CoRoT, Kepler, Catalina and MACHO, and new connectors or descriptors can be implemented. In addition to direct usage of the package and command line UI, the program can be used through a web interface. Users can create jobs for ”training” methods on given objects, querying databases and filtering outputs by trained filters. Preimplemented descriptors, classifier and connectors can be picked by simple clicks and their parameters can be tuned by giving ranges of these values. All combinations are then calculated and the best one is used for creating the filter. Natural separation of the data can be visualized by unsupervised clustering.

[ascl:1805.003]
lcps: Light curve pre-selection

lcps searches for transit-like features (i.e., dips) in photometric data. Its main purpose is to restrict large sets of light curves to a number of files that show interesting behavior, such as drops in flux. While lcps is adaptable to any format of time series, its I/O module is designed specifically for photometry of the Kepler spacecraft. It extracts the pre-conditioned PDCSAP data from light curves files created by the standard Kepler pipeline. It can also handle csv-formatted ascii files. lcps uses a sliding window technique to compare a section of flux time series with its surroundings. A dip is detected if the flux within the window is lower than a threshold fraction of the surrounding fluxes.

[ascl:2310.002]
lcsim: Light curve simulation code

lcsim creates artificial light curves using two algorithms. The first simulates Gaussian distributed light curves following a specific power spectral density (PSD) freely selectable by the user. The second algorithm simulates light curves following a specific PSD and matching a specific probability density function (PDF). The package provides methods to resample the simulated light curves and add "observational" noise. Furthermore, the package provides an interface to a SQLite3-based database to store and access the simulations.

[ascl:2205.013]
ld-exosim: Simulate biases using different limb darkening laws

ld-exosim selects the optimal (*i.e.* best estimator in a MSE sense) limb-darkening law for a given transiting exoplanet lightcurve and calculates the limb-darkening induced biases on various exoplanet parameters. Limb-darkening laws include linear, quadratic, logarithmic, square-root and three-parameter laws.

[ascl:1511.018]
LDC3: Three-parameter limb darkening coefficient sampling

LDC3 samples physically permissible limb darkening coefficients for the Sing et al. (2009) three-parameter law. It defines the physically permissible intensity profile as being everywhere-positive, monotonically decreasing from center to limb and having a curl at the limb. The approximate sampling method is analytic and thus very fast, reproducing physically permissible samples in 97.3% of random draws (high validity) and encompassing 94.4% of the physically permissible parameter volume (high completeness).

[ascl:1507.016]
Least Asymmetry: Centering Method

Lust, Nate B.; Britt, Daniel; Harrington, Joseph; Nymeyer, Sarah; Stevenson, Kevin B.; Ross, Emily L.; Bowman, William; Fraine, Jonathan

Least Asymmetry finds the center of a distribution of light in an image using the least asymmetry method; the code also contains center of light and fitting a Gaussian routines. All functions in Least Asymmetry are designed to take optional weights.

[ascl:1104.006]
LECTOR: Line-strengths in One-dimensional ASCII Spectra

LECTOR is a Fortran 77 code that measures line-strengths in one dimensional ascii spectra. The code returns the values of the Lick indices as well as those of Vazdekis & Arimoto 1999, Vazdekis et al. 2001, Rose 1994, Jones & Worthey 1995 and Cenarro et al. 2001. The code measures as many indices as you wish if the limits of two pseudocontinua (at each side of the feature) and the feature itself (i.e. Lick-style index definition) are provided. The Lick-style indices could be either expressed in pseudo-equivalent widths or in magnitudes. If requested the program provides index error estimates on the basis of photon statistics.

[ascl:2307.054]
LEFTfield: Forward modeling of cosmological density fields

LEFTfield forward models cosmological matter density fields and biased tracers of large-scale structure. The model, written in C++ code, is centered around classes encapsulating scalar, vector, and tensor grids. It includes the complete bias expansion at any order in perturbations and captures general expansion histories without relying on the EdS approximation; however, the latter is also implemented and results in substantially smaller computational demands. LEFTfield includes a subset of the nonlinear higher-derivative terms in the bias expansion of general tracers.

[ascl:2204.003]
legacystamps: Retrieve DESI Legacy Imaging Surveys cutouts

The Python module legacystamps provides easy retrieval, both standalone and scripted, of FITS and JPEG cutouts from the DESI Legacy Imaging Surveys through URLs provided by the Legacy Survey viewer.

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