FA-55783 / Astronomical coordinate conventions / Member archive

Celestial stereographic projection: Stereographic domain is replaced by TAN front-hemisphere validity · case 03

The adapter reports an incorrect valid while other fields remain valid.

Member previewVariant 3 · 3 implementations · 6 checks per implementation

Case contract

A supplied direction e,n,z is mapped by a stipulated stereographic sky chart with scale 2/(1+z), valid z>-1. Reference chart origin ox,oy is added only after projection. Exact antipode has no finite chart coordinate; inputs here have z>=-1. Output fields are defined by: plane_east = 2*d['e']/(1+d['z']) if d['z']>-1 else None; plane_north = 2*d['n']/(1+d['z']) if d['z']>-1 else None; valid = d['z']>-1; translated_east = d['ox']+2*d['e']/(1+d['z']) if d['z']>-1 else None; translated_north = d['oy']+2*d['n']/(1+d['z']) if d['z']>-1 else None; radial_scale = 2/(1+d['z']) if d['z']>-1 else None

Why this case matters

Catalog, detector, sky-coordinate, and spectroscopy adapters must preserve the association between numeric coordinates and their declared reference conventions.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
astronomical fixture 2	`{"plane_east": null, "plane_north": null, "radial_scale": null, "translated_east": null, "translated_north": null, "valid": true}`	`{"plane_east": null, "plane_north": null, "radial_scale": null, "translated_east": null, "translated_north": null, "valid": false}`	Failed

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This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

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