Download or view mithengesun.frink in plain text format
// Program to calculate sun crossing of the Infinite Corridor at MIT
// known as "MIThenge"
//
// More info at also http://web.mit.edu/planning/www/mithenge.html
// Thanks to Keith Winstein and Ken Olum for various data.
//
// For worked predictions, see https://futureboy.us/mithenge/
//
// Alan Eliasen, eliasen@mindspring.com
use mithengecorridor.frink
use cambridgetempFourier.frink
use sun.frink
sep = "\t"
preamble = ""
html = false
printall=false
if ARGS.contains["--html"]
{
sep = "<TD>"
preamble = "<TR><TD>"
html = true
}
if ARGS.contains["--printall"]
printall = true
out = ["degrees", "arcmin", "arcsec"]
dateOut = ### yyyy-MM-dd hh:mm:ss a zzz ###
tz = "US/Eastern"
date = beginningOfYear[now[], tz]
enddate = beginningOfYearPlus[date, 2, tz]
temperature = F[59]
while (date <= enddate)
{
date = sunSecantAzimuth[date, lat, long, corridorAzimuthMeeus, temperature, pressure]
// Now refine with temperature for that time of day.
temperature = cambridgeTemp[date]
date = sunSecantAzimuth[date, lat, long, corridorAzimuthMeeus, temperature, pressure]
[azimuth, altitude] = refractedSunAzimuthAltitude[date, lat, long, temperature, pressure]
print[preamble]
print[(date -> [dateOut, tz]) + "$sep"]
print[format[JD[date],day,5] + "$sep"]
print[format[altitude,degrees,2] + "$sep"]
print[format[F[temperature],1,0]]
radiusAngle = sunRadiusAngle[date]
if printall or (altitude < (0.91 degrees + radiusAngle) and altitude > -radiusAngle)
{
if !html
print["$sep*"]
[f1,f2,f3] = drawSuns[date, lat, long, temperature, pressure, corridorAzimuth]
if html
println["$sep\n $sep<A HREF=\"images/$f1\">\n <IMG SRC=\"images/$f2\" WIDTH=100 HEIGHT=80></A>\n $sep<A HREF=\"images/$f3\">[SVG]</A>"]
}
println[]
date = date + 1 day
}
// Function to draw the path of the sun as it crosses the corridor.
drawSuns[date, lat, long, temperature, pressure, corridorAzimuth] :=
{
tz = "US/Eastern"
g = new graphics
g.font["SansSerif", .05 deg]
d1 = date - 2 min
do
{
[az, alt] = refractedSunAzimuthAltitude[d1, lat, long, temperature, pressure]
drawSun[g, d1, lat, long, temperature, pressure]
d1 = d1 - 2 min
} while alt < 1.2 degrees
d1 = date + 2 min
do
{
[az, alt] = refractedSunAzimuthAltitude[d1, lat, long, temperature, pressure]
drawSun[g, d1, lat, long, temperature, pressure]
d1 = d1 + 2 min
} while alt > 0 degrees
drawSun[g, date, lat, long, temperature, pressure, true]
// Draw doorway aperture
g.color[0,0,0,.7]
g.drawRectSides[corridorAzimuth - .5 degrees, 0 degrees, corridorAzimuth + .5degrees, -.91 degrees]
// Draw vertical centerline
g.line[corridorAzimuth, 0 degrees, corridorAzimuth, -.91 degrees]
// Draw floor
g.fillRectSides[corridorAzimuth - 1 degree, 0 degrees, corridorAzimuth + 1 degree, .5 degrees]
// Text description
g.color[1,1,1]
df = ###yyyy-MM-dd hh:mm:ss a zzz###
g.font["SansSerif", "bold", .1 degrees]
g.text[(date->[df,tz]), corridorAzimuth, .2 degrees]
// Render files
sd = ###yyyy-MM-dd###
f1 = "sun" + (date->[sd, tz]) + ".png"
g.write[f1, 640, 480]
f2 = "sunthumb" + (date->[sd, tz]) + ".png"
g.write[f2, 100, 80]
f3 = "sun" + (date->[sd, tz]) + ".svg"
g.write[f3, 640, 480]
// g.show[]
return [f1,f2,f3]
}
// Draw a single sun image with time/date stamp.
drawSun[g, date, lat, long, temperature, pressure, yellow=false] :=
{
tz = "US/Eastern"
shortDate = ###hh:mm:ss a###
[azimuth, altitude] = refractedSunAzimuthAltitude[date, lat, long, temperature, pressure]
trueAz = (azimuth + 180 degrees) mod circle
// println["True azimuth at $date is " + (trueAz->degrees)]
ra = sunRadiusAngle[date]
da = 2 ra
// println["Radius angle is " + (ra->"degrees")]
// Draw the sun
if yellow
{
g.color[1,1,0,0.7]
g.fillEllipseCenter[trueAz, -altitude, da, da]
}
g.color[0,0,0]
g.drawEllipseCenter[trueAz, -altitude, da, da]
g.text[(date -> [shortDate, tz]), trueAz, -altitude]
// g.text[(date -> [shortDate, tz]), trueAz, -altitude]
}
Download or view mithengesun.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 19966 days, 20 hours, 51 minutes ago.