File talk:Sky.svg

The Python script to generate this map (same license as the image). Expects the downloaded catalog in the same directory. The SVG template ./svg_template.svg can be reverse-engineered easily from the compiled image.

#!/usr/bin/env python3

from math import sin
import re

southern_stars = 
northern_stars = 

catalog = open('./catalog')
stars = (
    {
        'id': s[0:4].strip(),
        'name': s[4:14].strip(),
        'ra':  (float(s[75:77])*15 + float(s[77:79])/4 + float(s[79:83])/240),
        'dec': int(s[83]+'1') * (int(s[84:86]) + int(s[86:88])/60 + int(s[88:90])/360),
        'mag': float(s[102:107]) if s[102:107].strip() else None,
        'sptype': s[127:147].strip(),
    } for s in catalog if len(s) > 160 and s[83:86].strip()
)

for star in stars:
    sptype = star['sptype'][0]
    if sptype == 'p':
        # Eta Car has spectral type "pec"
        sptype = 'O'

    ra = round(star['ra'], 4)
    if star['dec'] < 0:
        ra *= -1
    dec = round( 10 * ( 90 - abs(star['dec']) ), 4 )
    mag = 10 - 10*sin(star['mag']/20*3.1415)

    constellation = 
    if re.search('[A-Z][a-z]{2}$', star['name']):
        constellation = star['name'][-3:]

    svg_star = ('<use xlink:href="#{sptype}"'
                ' transform="translate(0 -{dec}) rotate({ra} 0 {dec}) scale({mag} {mag})"'
                ' class="spec-{sptype} {constellation}"/>\n').format(
        sptype=sptype, mag=mag, ra=ra, dec=dec, constellation=constellation)

    if star['dec'] >= 0:
        northern_stars += svg_star
    else:
        southern_stars += svg_star

catalog.close()

svg_tpl = open('./sky_template.svg')
svg = svg_tpl.read()
svg_tpl.close()

print(svg.format(northern_stars=northern_stars, southern_stars=southern_stars)) — Preceding unsigned comment added by Manuel Strehl (talk • contribs) 00:29, 25 March 2017 (UTC)