-- get positions needed to cast horoscope
function printplanet(name)
    planet = celestia:find(name)
    p_pos = marsframe:to(planet:getposition())
    p_vec = p_pos - o_pos
    printvector(name, p_vec:normalize())
end
function printvector(string, vec)
    if vec:length() < 0.5 then
	celestia:print("vector error")
    end
    positions:write(string .. " x=" .. vec.x .. " y=" .. vec.y .. " z=" .. vec.z.. "\n")
    -- celestia:print(string .. " x=" .. vec.x .. " y=" .. vec.y .. " z=" .. vec.z,20)
end
celestia:requestsystemaccess()
wait(0)
positions = io.open("/Users/dmm/documents/magic/astrology/points.txt", "w")
mars = celestia:find("Mars")
marsframe = celestia:newframe("equatorial", mars)
obs = celestia:getobserver()
o_pos = marsframe:to(obs:getposition()) 
horizon_normal = o_pos - marsframe:to(mars:getposition())
printvector("horizon_normal", horizon_normal:normalize())
planet_list = {"Sol", "Mercury", "Venus", "Earth", "Phobos", "Deimos", "Jupiter", "Saturn", "Uranus", "Neptune", "Pluto"}
for i,v in ipairs(planet_list) do
    printplanet(v)
end
-- find retrograde motion
current_time = celestia:gettime()
celestia:settime(current_time - 1)
for i,v in ipairs(planet_list) do
    positions:write("yesterday_")
    printplanet(v)
end
celestia:settime(current_time + 1)
for i,v in ipairs(planet_list) do
    positions:write("tomorrow_")
    printplanet(v)
end
celestia:settime(current_time)

positions:close()