Untitled

<body style="background: linear-gradient(to bottom right,#ffb032,#ff31d5);">
<b>keplerian elements</b>:<br>
<input type=text id="mass">M
<input type=button value="calculate" onClick="calc_cartesian()">(keplarian to cartesian)<br>
<input type=text id="sma">sma<br>
<input type=text id="ecc">ecc<br>
<input type=text id="inc">inc<br>
<input type=text id="aof">aop<br>
<input type=text id="ta">ta<br>
<input type=text id="ascn">ascn<br><br>
<b>cartesian elements:</b><br>
<input type=text id="rx">rx
<input type=button value="calculate" onClick="calc_keplarian()">(cartesian to keplerian)<br>
<input type=text id="ry">ry<br>
<input type=text id="rz">rz<br>
<input type=text id="vx">vx<br>
<input type=text id="vy">vy<br>
<input type=text id="vz">vz<br>
<script>
function calc_cartesian() {
var mass = document.getElementById("mass").value;
var sma = document.getElementById("sma").value;
var ecc = document.getElementById("ecc").value;
var inc = document.getElementById("inc").value;
var aof = document.getElementById("aof").value;
var ta = document.getElementById("ta").value;
var ascn = document.getElementById("ascn").value;
var grav_const = 6.6740831e-11;
var pi = 3.14159265358979323846;
var ascn_rad = ascn/180*pi;
var ta_rad = ta/180*pi;
var aof_rad = aof/180*pi;
var inc_rad = inc/180*pi;
var ecc_anom = Math.acos((Math.cos(ta_rad)+1*ecc)/(1+(ecc*Math.cos(ta_rad))));
if (ecc>1) {ecc_anom = Math.acosh((Math.cos(ta_rad)+(1*ecc))/(1+((1*ecc)*Math.cos(ta_rad))));}
var rad = sma*(1-(ecc*ecc))/(1+(ecc*Math.cos(ta_rad)));
var epsilon = Math.sqrt((grav_const*mass)/(Math.abs(sma)*rad*rad));
var x_prime = rad*Math.cos(ta_rad);
var y_prime = rad*Math.sin(ta_rad);
var I_prime = (-1)*sma*epsilon*Math.sin(ecc_anom);
var J_prime = (-1)*sma*Math.sqrt(1-(ecc*ecc))*epsilon*Math.cos(ecc_anom);
if (ecc>1) {J_prime = (-1)*sma*Math.sqrt((ecc*ecc)-1)*epsilon*Math.cos(ecc_anom);}
var px = (Math.cos(aof_rad)*Math.cos(ascn_rad))-(Math.sin(ascn_rad)*Math.sin(aof_rad)*Math.cos(inc_rad));
var py = (Math.cos(aof_rad)*Math.sin(ascn_rad))+(Math.cos(ascn_rad)*Math.sin(aof_rad)*Math.cos(inc_rad));
var pz = Math.sin(aof_rad)*Math.sin(inc_rad);
var qx = (-1)*(Math.sin(aof_rad)*Math.cos(ascn_rad))-(Math.sin(ascn_rad)*Math.cos(aof_rad)*Math.cos(inc_rad));
var qy = (-1)*(Math.sin(aof_rad)*Math.sin(ascn_rad))+(Math.cos(ascn_rad)*Math.cos(aof_rad)*Math.cos(inc_rad));
var qz = Math.cos(aof_rad)*Math.sin(inc_rad);
var rx = (x_prime*px)+(y_prime*qx);
var ry = (x_prime*py)+(y_prime*qy);
var rz = (x_prime*pz)+(y_prime*qz);
var vx = (I_prime*px)+(J_prime*qx);
var vy = (I_prime*py)+(J_prime*qy);
var vz = (I_prime*pz)+(J_prime*qz);
document.getElementById("rx").value = rx;
document.getElementById("ry").value = ry;
document.getElementById("rz").value = rz;
document.getElementById("vx").value = vx;
document.getElementById("vy").value = vy;
document.getElementById("vz").value = vz;
}
function calc_keplarian() {
var x = document.getElementById("rx").value;
var y = document.getElementById("ry").value;
var z = document.getElementById("rz").value;
var i = document.getElementById("vx").value;
var j = document.getElementById("vy").value;
var k = document.getElementById("vz").value;
var mass = document.getElementById("mass").value;
var grav_const = 6.6740831e-11;
var pi = 3.14159265358979323846;
var hx = (y*k)-(z*j);
var hy = (z*i)-(x*k);
var hz = (x*j)-(y*i);
var nx = (-1)*hy;
var ny = hx;
var n = Math.sqrt((nx*nx)+(ny*ny));
var h = Math.sqrt((hx*hx)+(hy*hy)+(hz*hz));
var r = Math.sqrt((x*x)+(y*y)+(z*z));
var v = Math.sqrt((i*i)+(j*j)+(k*k));
var ex = (1/(grav_const*mass))*((((v*v)-((grav_const*mass)/r))*x)-(((x*i)+(y*j)+(z*k))*i))
var ey = (1/(grav_const*mass))*((((v*v)-((grav_const*mass)/r))*y)-(((x*i)+(y*j)+(z*k))*j))
var ez = (1/(grav_const*mass))*((((v*v)-((grav_const*mass)/r))*z)-(((x*i)+(y*j)+(z*k))*k))
var ecc2 = Math.sqrt((ex*ex)+(ey*ey)+(ez*ez))
var inc2 = (180/pi)*Math.acos(hz/h)
var ascn2 = (180/pi)*Math.acos(nx/n)
var sma2 = ((h*h)/(1-(ecc2*ecc2)))/(grav_const*mass)
var aof2 = (180/pi)*Math.acos(((nx*ex)+(ny*ey))/(n*ecc2))
var ta2 = (180/pi)*Math.acos(((ex*x)+(ey*y)+(ez*z))/(ecc2*r))
if (0>ez) {
aof2 = 360-aof2}
if (0>ny) {
ascn2 = 360-ascn2}
if (0>rz) {
ta = 360-ta}
document.getElementById("sma").value = sma2;
document.getElementById("ecc").value = ecc2;
document.getElementById("inc").value = inc2;
document.getElementById("aof").value = aof2;
document.getElementById("ta").value = ta2;
document.getElementById("ascn").value = ascn2;
}
</script>