static private void vp(List <Body> bv, int nstep)
{
MathVector dacc = MathVector.makeMathVector();
MathVector dvel = MathVector.makeMathVector();
double dthf = 0.5 * BH.DTIME;
for (int i = 0; i < bv.Count; ++i)
{
Body b = bv[i];
MathVector acc1 = b.newAcc.cloneMathVector();
if (nstep > 0)
{
dacc.subtraction2(acc1, b.acc);
dvel.multScalar2(dacc, dthf);
dvel.addition(b.vel);
b.vel = dvel.cloneMathVector();
}
b.acc = acc1.cloneMathVector();
dvel.multScalar2(b.acc, dthf);
MathVector vel1 = b.vel.cloneMathVector();
vel1.addition(dvel);
MathVector dpos = vel1.cloneMathVector();
dpos.multScalar1(BH.DTIME);
dpos.addition(b.pos);
b.pos = dpos.cloneMathVector();
vel1.addition(dvel);
b.vel = vel1.cloneMathVector();
}
}
/**
* Create a HG object.
*
* @param b the body object
* @param p a vector that represents the body
*/
public static HG makeHG (Body b, MathVector p)
{
HG hg = new HG ();
hg.pskip = b;
hg.pos0 = p.cloneMathVector ();
hg.phi0 = 0.0;
hg.acc0 = MathVector.makeMathVector ();
return hg;
}
/**
* Create a HG object.
*
* @param b the body object
* @param p a vector that represents the body
*/
public static HG makeHG(Body b, MathVector p)
{
HG hg = new HG();
hg.pskip = b;
hg.pos0 = p.cloneMathVector();
hg.phi0 = 0.0;
hg.acc0 = MathVector.makeMathVector();
return(hg);
}