test pyephem and skyfield.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Ephem\n",
    "New moons for the year -500"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "import ephem"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "New moons for year -500:\n",
      "1/22\n",
      "2/21\n",
      "3/22\n",
      "3/23\n",
      "4/21\n",
      "5/20\n",
      "5/21\n",
      "6/19\n",
      "7/19\n",
      "8/17\n",
      "8/18\n",
      "9/16\n",
      "10/16\n",
      "11/14\n",
      "12/14\n"
     ]
    }
   ],
   "source": [
    "tau = 2.0 * ephem.pi\n",
    "\n",
    "babylon = ephem.Observer()\n",
    "babylon.epoch = '-500'\n",
    "babylon.lat, babylon.lon = \"32.535164526\", \"44.41916499\"\n",
    "babylon.date = ephem.date('-500/1/1')\n",
    "\n",
    "sun = ephem.Sun()\n",
    "moon = ephem.Moon()\n",
    "print(\"New moons for year -500:\")\n",
    "while babylon.date < ephem.date('-499/1/1'):\n",
    "    sun.compute(babylon.date)\n",
    "    moon.compute(babylon.date)\n",
    "    sunlon = ephem.Ecliptic(sun).lon\n",
    "    moonlon = ephem.Ecliptic(moon).lon\n",
    "\n",
    "    angle = (moonlon - sunlon) % tau\n",
    "    phase = angle * 30\n",
    "    if (6 < phase < 14):\n",
    "        year, month, day, _, _, _ = babylon.date.tuple()\n",
    "        print(f\"{month}/{day}\",)\n",
    "    babylon.date += 1"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Skyfield\n",
    "New moons for the year -500"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [],
   "source": [
    "from skyfield.api import load, Topos"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 28,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "New moons for year -500:\n",
      "1/27\n",
      "2/26\n",
      "4/26\n",
      "5/26\n",
      "6/24\n",
      "7/24\n",
      "9/21\n",
      "11/19\n"
     ]
    }
   ],
   "source": [
    "planets = load('de422.bsp')\n",
    "babylon = Topos(\"32.535164526 N\", \"44.41916499 E\")\n",
    "ts = load.timescale()\n",
    "t = ts.utc(-500, 1, 1)\n",
    "sun, moon, earth = planets['sun'], planets['moon'], planets['earth']\n",
    "\n",
    "r = ts.ut1(-500, 1, range(1, 365))\n",
    "print(\"New moons for year -500:\")\n",
    "for ti in r:\n",
    "    e = earth.at(ti)\n",
    "    _, slon, _ = e.observe(sun).apparent().ecliptic_latlon()\n",
    "    _, mlon, _ = e.observe(moon).apparent().ecliptic_latlon()\n",
    "    phase = (mlon.degrees - slon.degrees) % 360.0\n",
    "    if (6 < phase < 14):\n",
    "        print(f\"{ti.utc.month}/{ti.utc.day}\")"
   ]
  }
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