astrolabe display - Githubissues

rn123 / Calendrical-Tools

Calendrical tools for reckoning time.

https://rn123.github.io/Calendrical-Tools/

0 stars 0 forks source link

astrolabe display #4

Open rn123 opened 4 years ago

rn123 commented 4 years ago

Especially for the time of a new moon, generate astrolabe diagram for the location (default TBD).

rn123 commented 4 years ago

Sigh, lost the python code to generate the (animated) svg. The one generated file that I still have does have pretty good structure to show the logic. The python code

[x] reconstruct python to generate svg
[x] use as example topic for practice with GitHub pages
[x] use jinja2 template to fill in skeleton of image

rn123 commented 4 years ago

Basic requirements:

[ ] A minimal version should be an astrolabe plate grid with the moon (correct phase) in the correct grid location. This may also serve as a simplified graphic.
[x] Generated svg should, when opened in Inkscape, provide layers according to plate, limbs, etc. Especially the generous use of inkscape:label="ecliptic" inkscape:groupmode="layer" attributes in the svg groups.
[ ] Reconstruct the back of the astrolabe plate from scratch. I do not have a surviving svg. See Morrison pgs 111-114.
[x] Astrolabe generation code should take for input a time and location (longitude & latitude) and output a diagram showing the sky at that time and place.
[ ] Include "geometric construction" layers in order to document layout formulas.
[x] Optionally compute plate for clime instead of latitude.
[x] Astrolabe class to represent information required to draw and update.

rn123 commented 4 years ago

Back plate

[ ] Svg circular calendar

rn123 commented 4 years ago

Rete

[ ] Ecliptic should have static markings but, as part of the rete, also allow placement of sun, moon, and planets.
[ ] Divide ecliptic according to 24 solar terms used in Chinese calendar.
[ ] modern star list & stereographic projections
[ ] Ptlomey's star list (w/modern coordinates) & their stereographic projections
[ ] Display ecliptic as a calendar
[ ] Display ecliptic as zodiac
[ ] Display ecliptic as solar terms

rn123 commented 4 years ago

Currently, Astrolabe object computes the basic elements (centers and radii) and fills in a jinja2 template for the svg output. Started using svgpathtools to compute intersections of paths. Also, cairosvg is used to generate a png output. The cairosvg package also provides access to an xml parse tree object.

with open('ecliptic_division.svg') as fp:
    tree = cairosvg.parser.Tree(file_obj=fp)

for elem in tree.xml_tree:
    print(elem)

A more expressive representation would be a minimal svg boilerplate, parsed into an xml_tree and svgpathtools path representations that can be mixed and matched to generate a custom astrolabe output.

rn123 commented 4 years ago

Currently, Astrolabe object computes the basic elements (centers and radii) and fills in a jinja2 template for the svg output. @rn123 Note: Should compare liquid vs jinja2 templates. Also, what templates are used in DASH?