Download or view transit.frink in plain text format
// This program animates the transit of Venus across the sun on 2012-06-05.
use planets.frink
use sun.frink
timezone = "Mountain"
lat = 39.58560 degrees North
long = 104.89598 degrees West
/*lat = DMS[40, 33, 35.84] North
long = DMS[105,04,57.64] West*/
df = ### yyyy-MM-dd-HH:mm ###
g = new graphics
win = g.show[]
//for planet = [Planet.Mercury, Planet.Venus]
planet = Planet.Venus
startdate = #2012-06-05 04:00 PM#
enddate = sunset[startdate, lat, long]
for d = #2012-06-05 04:00 PM# to enddate step 10 s
{
[azsun, altsun] = refractedSunAzimuthAltitude[d, lat, long]
[azp, altp] = planet.refractedAzimuthAltitude[d, lat, long]
separation = angularSeparation[azsun, altsun, azp, altp]
sunRadius = sunRadiusAngle[d]
venusRadius = planet.radiusAngle[d]
//println[venusRadius -> [0, "deg", "arcmin", "arcsec"]]
flag = ""
if separation < sunRadius + venusRadius
{
flag = "*"
if separation < sunRadius - venusRadius
flag = "**"
g = new graphics
[skyr,skyg,skyb] = skyDarkness[d, lat, long, [[.1,.1,.1], [.1,.1,.2], [.1,.1,.3], [.1,.1,.4], [.8,.8,1]]]
g.backgroundColor[skyr, skyg, skyb]
// Draw the sun
g.color[1,1,0] // Yellow
g.fillEllipseCenter[(azsun-azsun) cos[-altsun], -(altsun-altsun), 2 sunRadius, 2 sunRadius]
// Draw Venus
// How much more black could it be? The answer is none. None more black.
g.color[0,0,0]
g.fillEllipseCenter[(azp-azsun) cos[-altp], -(altp-altsun), 2 venusRadius, 2 venusRadius]
// g.add[planet.drawPolygonRelativeToZenith[d, lat, long, azp, -altp, venusRadius, true]]
win.replaceGraphics[g]
}
println[(d->timezone) + "\t" + format[separation,"deg", 5] + "\t$flag" ]
}
Download or view transit.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 19965 days, 18 hours, 1 minutes ago.