$f : x \mapsto \frac{1}{2 \pi \cdot \sigma} \exp \left[ -\frac{1}{2} \left( \frac{x - \mu}{\sigma} \right)^2 \right]$
where $$\mu = \mathtt{mean}$$ and $$\sigma = \mathtt{std}$$.
• mean (float, optional, default: 0.5) – Mean of the Gaussian PDF. The default value places the mean in the middle of the particle layer (at $$x = 0.5$$).
• std (float, optional, default: 1/6) – Standard deviation of the Gaussian PDF. The default value is such that the integral of the Gaussian PDF over the $$[\mu - 0.5, \mu + 0.5]$$ interval is about 99.7% (3σ).