Peter Sharpe's Missile homing script- syntax updated

// Final homing
//set Target to "nameoftarget".
//YOU MUST MANUALLY TARGET YOUR TARGET BEFORE EXECUTING THIS PROGRAM.
//Editable Parameters
set explosionradius to 8.
set iterations to 8.
set initialguess to 15.
set pitchangle to 15.
Clearscreen.
//Do Targeting
print "Enemy heat signature acquired. Homing!!!".
print"Missile by Peter Sharpe".
print"Syntax updated to Kos 1.3.0.0 from 1.1.3.0".
print"By NotUrGenre".
//Launch Sequence
lock throttle to 1.
//Set up outputs
print "Time to interception:" at (6,0).
print "Distance to Target:" at (7,0).
print "Steering Error:" at (8,0).
//Take steering control, lock it to "steeringangle"
set steeringangle to up+target:direction.
sas off.
lock steering to steeringangle.
//Arm the warhead to trigger with radius of "explosionradius" + 1 frame to decouple.
when t<explosionradius/50+0.05 or target:distance<50 then {stage. set vectordraw:show to false.}
print "Warhead armed. Initiating homing algorithm." at (9,0).
//Homing Algorithm, infinite loop
set t to 10.
until 0
{
    set steeringangle to up+target:direction.
    set rpos to (0-1)*(target:Position).
    set rvel to (ship:velocity:surface-target:velocity:orbit).
if target:loaded {set rvel to ship:velocity:surface-target:velocity:surface.}.
if altitude>35000 or target:altitude>35000 {set rvel to ship:velocity:orbit-target :velocity:orbit.}.
    set amag to eng2:maxthrust/(ship:mass*9.81).
//Solve for t, where 0=at^4+bt^2+ct+d. First get coefficients
    set a to 0-((amag)^2)/4.
    set b to (rvel:sqrmagnitude).
    set c to 2*(rvel*rpos).
    set d to (rpos:sqrmagnitude).
//Do a few Newton-Raphson iterations:
    set timeguesses to list().
    timeguesses:add(initialguess).
    set position to 0.
until position>=iterations
    {
    timeguesses:add(position-(a*timeguesses[position]^4+b*timeguesses[position]^2+c*timeguesses[position]+d)/(4*a*timeguesses[position]^3+2*b*timeguesses[position]+c)).
    set position to position+1.
    }.
    set initialguess to abs(timeguesses[iterations]).
//Then calculate your desired direction
    set t to abs(timeguesses[iterations])/1.15.
if altitude>35000 {set t to abs(timeguesses[iterations]).}.
print t at (22,10).
print target:distance at (20,12).
    set steeringvector to (v((0-2)*(rpos:x+(rvel:x)*t)/(t^2),(0-2)*(rpos:y+(rvel:y)*t)/(t^2),(0-2)*(rpos:z+(rvel:z)*t)/(t^2))+6*(up:vector)).
    set steeringangle to steeringvector.//:direction.
print vectorangle(steeringvector,ship:facing:vector) at (16,14).
    set Vectordraw TO VECDRAWARGS(v(0,0,0), steeringvector:normalized, rgb(1,0.5,0.5),"", 12.0, true ).
}.