flat: Flat (Improper Uniform) Prior Distribution

In clmstan: Cumulative Link Models with 'CmdStanR'

Flat (Improper Uniform) Prior Distribution

Description

Creates a flat (improper uniform) distribution object for use with prior(). A flat prior assigns equal probability density to all values, which is improper (does not integrate to 1) but can be used when the likelihood provides sufficient information for identification.

Usage

flat()

Value

An object of class "clm_dist" representing a flat distribution.

Note

Flat priors are supported for:

• Regression coefficients (class "b")

• Threshold classes ("Intercept", "c1", "cpos")

Using flat priors may lead to improper posteriors if the likelihood does not provide sufficient information. For thresholds with ordered constraints, Stan's internal transformation provides implicit regularization.

See Also

prior(), normal(), student_t(), cauchy()

Examples

# Create a flat prior for regression coefficients
prior(flat(), class = "b")

# Flat prior for thresholds (flexible)
prior(flat(), class = "Intercept")

clmstan documentation built on June 29, 2026, 5:06 p.m.