Function step_constant_rate 

pub fn step_constant_rate(
    q: DQuat,
    omega_body_rad_s: DVec3,
    dt_s: f64,
) -> Result<DQuat, CoreError>

Advances the attitude by dt_s under a body rate that is constant over the step: q ⊗ exp(½ ω_B Δt), then renormalized.

Errors

As renormalize, which only fails if q or the rotation is not finite.