classify method
Classifies a damping ratio zeta into under/critical/over-damped.
Implementation
DampingKind classify(double zeta) {
if ((zeta - 1.0).abs() < 0.001) return DampingKind.critical;
return zeta < 1.0 ? DampingKind.underdamped : DampingKind.overdamped;
}