// attempt to calculate extra damping to provide 30% critical damping

var targetDampingPct = 30;   // target value (% critical damping)
var tolerance = 0.01;        // tolerance (stop when within this value of target)

// iterate up to 10 times to attempt to converge on target % critical
for(int n = 0; n < 10; ++n)
{
    // run with current inputs and get vessel results
    var results = RunAnalysis(InteractiveSpread, InteractiveConfig, new NoFailure());
    var vessel = results.Vessel;
    
    // calculate current differences from target % critical
    var errx = Math.Abs(vessel.CriticalX - targetDampingPct);
    var erry = Math.Abs(vessel.CriticalY - targetDampingPct);
    var errn = Math.Abs(vessel.CriticalN - targetDampingPct);
    
    // stop iterating if within tolerance
    if(errx < tolerance && erry < tolerance && errn < tolerance) break;
    
    // calculate expected extra damping values
    var factor = 25.0 / Math.PI;
    
    var xdamp = targetDampingPct * vessel.MassX.Tonnes / (factor * vessel.NaturalPeriodX.Seconds) -
        (vessel.LinearDampingX - vessel.LinearExtraDampingX).KilonewtonsPerMetrePerSecond;

    var ydamp = targetDampingPct * vessel.MassY.Tonnes / (factor * vessel.NaturalPeriodY.Seconds) -
        (vessel.LinearDampingY - vessel.LinearExtraDampingY).KilonewtonsPerMetrePerSecond;

    var ndamp = targetDampingPct * vessel.MassN.TonneMetresSquared / (factor * vessel.NaturalPeriodN.Seconds) -
        (vessel.LinearDampingN - vessel.LinearExtraDampingN).KilonewtonMetresPerRadianPerSecond;
        
    // set new extra damping for next iteration
    InteractiveConfig.Settings.ExtraDampingSway = LinearDamping.FromKilonewtonsPerMetrePerSecond(xdamp);
    InteractiveConfig.Settings.ExtraDampingSurge = LinearDamping.FromKilonewtonsPerMetrePerSecond(ydamp);
    InteractiveConfig.Settings.ExtraDampingYaw = RotationalLinearDamping.FromKilonewtonMetresPerRadianPerSecond(ndamp);
}