Download or view moonangle.frink in plain text format
// Program to calculate the minimum and maximum diameter of the moon as seen
// from earth over a specified time span.
use sun.frink
minangle = 1000 radians
maxangle = 0 radians
closestAngle = 0 radians
startDate = #2000-01-01#
endDate = #2010-01-01#
for date= startDate to endDate step 1 hours
{
// Calculate geocentric angle (as seen from center of earth.)
angle = 2 moonRadiusAngle[date]
// Also calculate angle as seen from closest position on earth.
closeAngle = 2 arcsin[moonradius / (moonradius + moonDistance[date] - earthradius)]
if (angle < minangle)
minangle = angle
if (angle > maxangle)
maxangle = angle
if (closeAngle > closestAngle)
closestAngle = closeAngle
}
println["Min is " + (minangle->"degrees")]
println["Max is " + (maxangle->"degrees")]
println["Closest angle is " + (closestAngle->"degrees")]
println[]
println["Interval estimate:"]
d = new interval[startDate, endDate]
aa = 2 moonRadiusAngle[d]
println[aa->"degrees"]
Download or view moonangle.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, eliasen@mindspring.com