require 'spice_rub'
require 'gnuplotrb'

SpiceRub::KernelPool.instance.load_folder("spec/data/kernels")

moon = SpiceRub::Body.new(:moon)
moon_orbit = 86400 * 27
start = SpiceRub::Time.parse("22 Aug 2016")

times = SpiceRub::Time.time_series(start, start + moon_orbit, step: 3600)
distances = times.map { |t| moon.distance_from(earth, t) }

GnuplotRB::Plot.new(
  [[times.map(&:et), distances], notitle: true] ,title: 'Distance of Moon from Earth v/s Time', with: 'lines')