HalfNormal
Canonical half-normal prior family on non-negative support.
Parameters
| Argument | Symbol | Meaning | Default |
|---|---|---|---|
std |
\(\sigma\) | Half-normal scale parameter | 1.0 |
random_state |
- | RNG seed / generator | None |
Implementation Parameterization
The implementation uses the canonical half-normal family on [0, \infty).
No shift parameter is exposed.
\[
f(x;\sigma) =
\sqrt{\frac{2}{\pi\sigma^2}}
\exp\left(-\frac{x^2}{2\sigma^2}\right)
\]
Region
\[
x \in [0,\infty)
\]