Comparison with Astropy

We highlight some of the major packages in Python's astropy ecosystem and their corresponding implementations in the Julia ecosystem. This is an actively evolving document, and suggested additions are welcomed.

Affiliated/coordinated packages in Julia

While there is a clear demarcation between core, coordinated, and affiliated packages in Python, this is not really the case in Julia. Composability is a core feature of the language, allowing for interactions between packages to occur fairly naturally.

Astropy core packages

Data structures and transformations

Python	Julia	Description
`astropy.constants`
	SymbolicML/DynamicQuantities.jl	Efficient and type-stable physical quantities in Julia
	JuliaPhysics/PhysicalConstants.jl	Collection of fundamental physical constants with uncertainties
	PainterQubits/Unitful.jl	Physical quantities with arbitrary units
	UnitfulAstro.jl	Astronomical units and things
`astropy.units`
	SymbolicML/DynamicQuantities.jl	Efficient and type-stable physical quantities in Julia
	JuliaPhysics/PhysicalConstants.jl	Collection of fundamental physical constants with uncertainties
	PainterQubits/Unitful.jl	Physical quantities with arbitrary units
	UnitfulAstro.jl	Astronomical units and things
`astropy.nddata`
`astropy.nddata`	rafaqz/DimensionalData.jl	Named dimensions and indexing for julia arrays and other data
`astropy.table`
	JuliaData/DataFrames.jl	In-memory tabular data in Julia
	JuliaAPlavin/FlexiJoins.jl	`FlexiJoins.jl` is a fresh take on joining tabular or non-tabular datasets in Julia.
	gcalderone/SortMerge.jl	A Julia implementation of the Sort-merge join algorithm
`astropy.time`
`astropy.time`	AstroTime.jl	Astronomical time keeping
`astropy.timeseries`
	JuliaDSP/DSP.jl	Filter design, periodograms, window functions, and other digital signal processing functionality
	LombScargle.jl	Compute Lomb-Scargle periodogram
	JuliaStats/TimeSeries.jl	Time series toolkit for Julia
	BoxLeastSquares.jl	Compute box-least-squares periodogram
`astropy.coordinates`
	EphemerisSources.jl	Meta package for accessing JPL HORIZONS and SPICE sources
	PerezHz/HORIZONS.jl	An interface to NASA-JPL HORIZONS system and other Solar System Dynamics APIs in Julia
	SPICE.jl	SPICE data retrieval and usage
	SkyCoords.jl	Astronomical coordinate systems
`astropy.wcs`
`astropy.wcs`	WCS.jl	World Coordinate System transformations
`astropy.modeling`
	jump-dev/JuMP.jl	Modeling language for Mathematical Optimization (linear, mixed-integer, conic, semidefinite, nonlinear)
	SciML/NonlinearSolve.jl	High-performance and differentiation-enabled nonlinear solvers (Newton methods), bracketed rootfinding (bisection, Falsi), with sparsity and Newton-Krylov support
	SciML/Optimization.jl	Mathematical Optimization in Julia. Local, global, gradient-based and derivative-free. Linear, Quadratic, Convex, Mixed-Integer, and Nonlinear Optimization in one simple, fast, and differentiable interface
`astropy.uncertainty`
	JuliaPhysics/Measurements.jl	Error propagation calculator and library for physical measurements. It supports real and complex numbers with uncertainty, arbitrary precision calculations, operations with arrays, and numerical integration
	MonteCarloMeasurements.jl	Propagation of distributions by Monte-Carlo sampling: Real number types with uncertainty represented by samples
	JuliaAPlavin/Uncertain.jl	Handle uncertain values with ease and performance!
	JuliaStats/Distributions.jl	A Julia package for probability distributions and associated functions

Files, I/O, and Communication

Python	Julia	Description
`astropy.io.fits`
	emmt/OIFITS.jl	Support for OI-FITS
	CFITSIO.jl	Reading and writing FITS files
	emmt/EasyFITS.jl	Using FITS files made easier for Julia
	barrettp/FITS.jl	A Julia Flexible Image Transport System (FITS) file IO package
	FITSIO.jl	Reading and writing FITS files
	JuliaAPlavin/SkyImages.jl	Load astronomical images of the sky and process them with convenient, general, and composable functions.
`astropy.io.ascii`
`astropy.io.ascii`	FixedWidthTables.jl	Read fixed width (so-called ASCII) tables
`astropy.io.votable`
	JuliaAPlavin/VLBIData.jl	Work with data formats common in very long baseline interferometry (VLBI)
	JuliaAPlavin/VirtualObservatory.jl	Access remote data and services that follow VO protocols
	JuliaAPlavin/VOTables.jl	Read and write VOTable files

Computations and Utilities

Python	Julia	Description
`astropy.cosmology`
`astropy.cosmology`	Cosmology.jl	Distances in the universe
`astropy.convolution`
	JuliaDSP/DSP.jl	Filter design, periodograms, window functions, and other digital signal processing functionality
	JuliaImages/ImageFiltering.jl	ulia implementations of multidimensional array convolution and nonlinear stencil operations
`astropy.utils.iers`
`astropy.utils.iers`	EarthOrientation.jl	Earth orientation parameters
`astropy.visualization`
	AstroImages.jl	Load, manipulate, and visualize astronomical images
	AstroImages.jl	Load, manipulate, and visualize astronomical images
	AstroImages.jl	Load, manipulate, and visualize astronomical images
	sefffal/PairPlots.jl	Beautiful and flexible visualizations of high dimensional data
	JuliaAPlavin/SkyImages.jl	Load astronomical images of the sky and process them with convenient, general, and composable functions.
`astropy.stats`
	mileslucas/BiweightStats.jl	Robust statistics based on the biweight transform
	JuliaStats	Statistics and Machine Learning made easy in Julia

Astropy coordinated packages

Python	Julia	Description
`asdf-astropy`
`asdf-astropy`	eschnett/ASDF2.jl	ASDF, the Advanced Scientific Data Format
`astropy-healpix`
`astropy-healpix`	ziotom78/Healpix.jl	Implementation of Healpix spherical tesselation scheme in pure Julia
`astroquery`
`astroquery`	JuliaAPlavin/VirtualObservatory.jl	Access remote data and services that follow VO protocols
`ccdproc`
`ccdproc`	CCDReduction.jl	Common CCD image processing routines
`photutils`
`photutils`	Photometry.jl	Aperture photometry
`regions`
`regions`	Photometry.jl	Aperture photometry
`reproject`
`reproject`	Reproject.jl	Astronomical image reprojection
`specreduce`
	ajwheeler/Korg.jl	Theoretical stellar spectra from 1D model atmospheres and linelists, assuming LTE
	Spectra.jl	Utilities for interfacing with astronomical spectra and synthetic spectra libraries
	fjebaker/SpectralFitting.jl	✨🛰 Fast and flexible spectral fitting in Julia
`specutils`
	ajwheeler/Korg.jl	Theoretical stellar spectra from 1D model atmospheres and linelists, assuming LTE
	Spectra.jl	Utilities for interfacing with astronomical spectra and synthetic spectra libraries
	fjebaker/SpectralFitting.jl	✨🛰 Fast and flexible spectral fitting in Julia