skyplothelper#
skyplothelper#
Astronomy visualization toolkit for matplotlib + astropy WCSAxes.
All-sky projections, custom WCS frames, spherical-region geometry, tilted
globes, cone (z-RA) wedge plots, HEALPix utilities, FITS image quicklook, an
interactive plotly/Dash export backend, and the everyday plot annotations that
go with them — from a single import skyplothelper as sph.
import skyplothelper as sph
import matplotlib.pyplot as plt
fig, ax = sph.allsky_figure(projection="AIT", center=180)
sph.add_plane_overlay(ax, plane="ecliptic", color="orange")
sph.add_constellation_boundaries(ax)
sph.add_survey_footprint(ax, survey="sdss")
plt.show()
Tip
New here — human or AI agent? Call sph.overview() for the frame-first
model and coordinate conventions, and sph.recipes('<keyword>') (e.g.
sph.recipes('cube')) for copy-paste recipes. Agents can ingest the same
catalog from llms.txt (a concise map) and
llms-full.txt (the full recipe corpus)
served at the site root.
Core install is just numpy + matplotlib + astropy; optional features are per-extra. One line grabs everything.
The package explained subsystem by subsystem — what each piece does, how it fits together, worked examples, and the gotchas.
A visual index of what skyplothelper can draw — all-sky maps, fields, globes, cones, HEALPix, regions, legends, and more — with starter code for each.
In-depth, runnable walkthroughs of complete workflows — from your first frames to catalogs, globes, HEALPix, and interactive maps.
Every public function and class, grouped by subsystem, with auto-generated signatures from the source.
Release notes and version history.
About#
skyplothelper grew out of years of day-to-day research plotting — the
recurring need to put astronomical data on the sky correctly (projections,
coordinate conventions, the antimeridian seam) and presentably (publication
ticks, beams, scale bars, refined styling) without rebuilding the same
scaffolding for every paper. It builds on astropy’s WCSAxes rather than
replacing it: every frame is a real WCSAxes you can keep customizing with
the full matplotlib + astropy toolbox.
The package covers the typical sky-plot workflow end to end — frame construction across 32 projections, coordinate conversions and FITS-header utilities, tick/grid/label control, overlays (coordinate planes, survey footprints, constellations, beams, rulers, reticles), set-algebraic spherical regions, globe and planetary maps, cosmology cone diagrams, HEALPix binning and rendering, catalog queries, vector fields on the sphere, and an interactive plotly backend that mirrors the matplotlib API.
pip install skyplothelper # core: numpy, matplotlib, astropy>=6.0, shapely, healpy
pip install skyplothelper[all] # everything optional
skyplothelper is BSD-3-Clause licensed. Cite via the repository’s
CITATION.cff. Bug reports and contributions are welcome on
GitHub — it’s maintained by a
single developer with limited time, so responses come as time allows; the
contributing
guide
covers what to expect.