Convert VIF to Target Variance — vif_to_variance_fit • DPprior

Computes the target variance from a Variance Inflation Factor.

Usage

vif_to_variance_fit(mu_K, vif)

Arguments

mu_K: Numeric; target expected number of clusters.
vif: Numeric; Variance Inflation Factor (must be > 1).

Value

Numeric; target variance: vif * (mu_K - 1).

Details

The VIF relates variance to the shifted mean (mu_K - 1): $$Var(K_J) = VIF \cdot (\mu_K - 1)$$

This parameterization is natural for the shifted NegBin approximation.

See also

confidence_to_vif_fit, DPprior_fit

Examples

if (FALSE) { # \dontrun{
vif_to_variance_fit(5, 2.5)  # 10 = 2.5 * (5 - 1)
} # }