// JavaScript Document
// Copyright Emory Department of Physics, 2008.
// Code written by Scott Meves.
// Equations and calcuations applied by Horace Dale.
// VSOP87 converted from libnova-0.7.0 under GNU-GPL.
// Revised 01/04/08 J.Boss

function speed(start)
{
      finish = new Date();
      elapsed = finish - start;
      elapsed = elapsed / 1000;
	  return elapsed;
} 

function commaSplit(srcNumber) {
	var txtNumber = '' + srcNumber;
	var rxSplit = new RegExp('([0-9])([0-9][0-9][0-9][,.])');
	var arrNumber = txtNumber.split('.');
	arrNumber[0] += '.';
	do {
		arrNumber[0] = arrNumber[0].replace(rxSplit, '$1,$2');
	} while (rxSplit.test(arrNumber[0]));
	if (arrNumber.length > 1) {
		return arrNumber.join('');
	}
	else {
		return arrNumber[0].split('.')[0];
	}
}

function calculateJD(cdDate){
	var year = cdDate.getUTCFullYear()
	var month = cdDate.getUTCMonth() + 1
	if (month<3)
	{  year = year - 1
	   month = month + 12 }
	var day = cdDate.getUTCDate()
	var hour = cdDate.getUTCHours()
	var min = cdDate.getUTCMinutes()
	var sec = cdDate.getUTCSeconds()
	
	var A = parseInt(year/100)
	var B = 2-A +parseInt(A/4)
	
	var E = hour/24 + min/1440 + sec/(8.64*Math.pow(10,4))
	
	var jd = parseInt(365.25*(year+4716)) + parseInt(30.6001 * (month + 1)) + day + B - 1524.5 + E
	
	// correct for dynamical time
	// 2008: 65.2 seconds. 65.2 / (24*60*60) = .0007546296
	
	jd = jd + .0007546296
	
	return jd;
}

function UTCdate(d){
	var weekday=new Array("Sun","Mon","Tue","Wed","Thu","Fri","Sat")
	var monthname=new Array("Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec")
	utc = weekday[d.getUTCDay()] + " ";
	utc += monthname[d.getUTCMonth()] + " "
	utc += d.getUTCDate() + " "
	if (d.getUTCHours() < 10) utc+="0";
	utc += d.getUTCHours() + ":"
	if (d.getUTCMinutes() < 10) utc+="0";
	utc += d.getUTCMinutes() + ":"
	if (d.getUTCSeconds() < 10) utc+="0";
	utc += d.getUTCSeconds() + " UTC "
	utc += d.getUTCFullYear() + " "
	return utc;
}

function calc_series (array, t)
{
	
	value = 0;
	
	for (i=0; i<array.length; i++){
	value += array[i][0] * Math.cos(array[i][1]+array[i][2]*t) 
	}
	
	return value;
}

function getEarthHelio(JD)
{
	t = (JD - 2451545.0) / 365250.0;
	t2 = t * t;
	t3 = t2 * t;
	t4 = t3 * t;
	t5 = t4 * t;

	L0 = calc_series(el0, t);
	L1 = calc_series(el1, t);
	L2 = calc_series(el2, t);
	L3 = calc_series(el3, t);
	L4 = calc_series(el4, t);
	L5 = calc_series(el5, t);
	L = (L0 + L1 * t + L2 * t2 + L3 * t3 + L4 * t4 + L5 * t5);
	
	B0 = calc_series(eb0, t);
	B1 = calc_series(eb1, t);
	B2 = calc_series(eb2, t);
	B3 = calc_series(eb3, t);
	B4 = calc_series(eb4, t);
	B5 = calc_series(eb5, t);
	B = (B0 + B1 * t + B2 * t2 + B3 * t3 + B4 * t4 + B5 * t5);

	R0 = calc_series(er0, t);
	R1 = calc_series(er1, t);
	R2 = calc_series(er2, t);
	R3 = calc_series(er3, t);
	R4 = calc_series(er4, t);
	R5 = calc_series(er5, t);
	R = (R0 + R1 * t + R2 * t2 + R3 * t3 + R4 * t4 + R5 * t5);

	E = new Array(3);
	E[0] = L;
	E[1] = B;
	E[2] = R;
	
	return E;
}

function getMarsHelio(JD)
{
	t = (JD - 2451545.0) / 365250.0;
	t2 = t * t;
	t3 = t2 * t;
	t4 = t3 * t;
	t5 = t4 * t;

	L0 = calc_series(ml0, t);
	L1 = calc_series(ml1, t);
	L2 = calc_series(ml2, t);
	L3 = calc_series(ml3, t);
	L4 = calc_series(ml4, t);
	L5 = calc_series(ml5, t);	
	L = (L0 + L1 * t + L2 * t2 + L3 * t3 + L4 * t4 + L5 * t5);
	
	B0 = calc_series(mb0, t);
	B1 = calc_series(mb1, t);
	B2 = calc_series(mb2, t);
	B3 = calc_series(mb3, t);
	B4 = calc_series(mb4, t);
	B5 = calc_series(mb5, t);
	B = (B0 + B1 * t + B2 * t2 + B3 * t3 + B4 * t4 + B5 * t5);
	
	R0 = calc_series(mr0, t);
	R1 = calc_series(mr1, t);
	R2 = calc_series(mr2, t);
	R3 = calc_series(mr3, t);
	R4 = calc_series(mr4, t);
	R5 = calc_series(mr5, t);
	R = (R0 + R1 * t + R2 * t2 + R3 * t3 + R4 * t4 + R5 * t5);

	M = new Array(3);
	M[0] = L;
	M[1] = B;
	M[2] = R;
	
	return M;
}

function calcDistance(el,eb,er,ml,mb,mr)
{
	x = mr * Math.cos(mb) * Math.cos(ml) - er * Math.cos(el) * Math.cos(eb);
	y = mr * Math.cos(mb) * Math.sin(ml) - er * Math.sin(el) * Math.cos(eb);
	z = mr * Math.sin(mb) - er * Math.sin(eb);
	
	// Correction for Barycenter

         Q = 3.8048177 + (8399.711184*t);
	 u = (Math.cos(Q) * 0.0000312) - x;
	 v = (Math.sin(Q) * 0.0000312) - y;

	
	distance = Math.sqrt(Math.pow(u,2)+Math.pow(v,2)+Math.pow(z,2));
	// distance = Math.sqrt(Math.pow(x,2)+Math.pow(y,2)+Math.pow(z,2));
	
	return distance;
}

function lightTime(d)
{
	lt = d * .0057755183; //in days
	return lt;
}

function round_num(x,places) {
        return (Math.round(x*Math.pow(10,places)))/Math.pow(10,places)
}