Inverse-Gamma(shape, rate) prior specification for a variance parameter.
Parameterisation: p(σ² | α, β) ∝ (σ²)^{−(α+1)} · exp(−β/σ²) where α = shape, β = rate.
p(σ² | α, β) ∝ (σ²)^{−(α+1)} · exp(−β/σ²)
α
β
Common choices:
{ shape: 2, rate: 1 }
{ shape: 0.001, rate: 0.001 }
Rate parameter β > 0.
Shape parameter α > 0.
Inverse-Gamma(shape, rate) prior specification for a variance parameter.
Parameterisation:
p(σ² | α, β) ∝ (σ²)^{−(α+1)} · exp(−β/σ²)whereα= shape,β= rate.Common choices:
{ shape: 2, rate: 1 }(mode = 1/3){ shape: 0.001, rate: 0.001 }