medievalPlanets.frink

Download or view medievalPlanets.frink in plain text format

// Identifying a medieval astronomical diagram
// https://mobile.twitter.com/MaxFagin/status/1619826334460678146

use planets.frink

g = new graphics
for p = [Planet.Mercury, Planet.Venus, Planet.Mars, Planet.Jupiter, Planet.Saturn]
{
   pl = new polyline
   
   for d = now[] to now[] + 2 year step 5 day
   {
      [ra, decl, dist] = p.geocentricCoordinates[d]
      epsilon = trueObliquityOfEcliptic[d]
      [lambda, beta] = raDeclToEcliptical[ra, decl, epsilon]
      pl.addPoint[beta, JD[d]]
   }

   g.color[randomFloat[0,.7], randomFloat[0,.7], randomFloat[0,.7]]
   [x,y] = first[pl.getPoints[]]
   g.text[p.getName[], x, y, "center", "bottom"]
   [x,y] = last[pl.getPoints[]]
   g.text[p.getName[], x, y, "center", "top"]
   g.add[pl]
}

pl = new polyline

for d = now[] to now[] + 2 year step 1 day
{
   [ra,decl] = moonApparentRADecl[d]
   epsilon = trueObliquityOfEcliptic[d]
   [lambda, beta] = raDeclToEcliptical[ra, decl, epsilon]
   pl.addPoint[beta, JD[d]]
}

g.color[randomFloat[0,.7], randomFloat[0,.7], randomFloat[0,.7]]
[x,y] = first[pl.getPoints[]]
g.text["Moon", x, y, "center", "bottom"]
[x,y] = last[pl.getPoints[]]
g.text["Moon", x, y, "center", "top"]
g.add[pl]

g.show[]
g.write["medievalPlanets.png", 300, 1000]


Download or view medievalPlanets.frink in plain text format


This is a program written in the programming language Frink.
For more information, view the Frink Documentation or see More Sample Frink Programs.

Alan Eliasen was born 19964 days, 22 hours, 13 minutes ago.