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Normal Prior

Source: R/bage_prior-constructors.R
N.Rd

Use independent draws from a normal distribution to model a main effect or interaction. Typically used with variables other than age or time, such as region or ethnicity, where there is no natural ordering.

Usage

N(s = 1)

Arguments

s

Scale for the standard deviation. Default is 1.

Value

An object of class "bage_prior_norm".

Details

Argument s controls the size of errors. Smaller values for s tend to give more tightly clustered estimates.

Mathematical details

$$\beta_j \sim \text{N}(0, \tau^2)$$

where \(\beta\) is the main effect or interaction.

Parameter \(\tau\) has a half-normal prior $$\tau \sim \text{N}^+(0, \mathtt{s}^2),$$ where s is provided by the user.

See also

  • NFix() Similar to N() but standard deviation parameter is supplied rather than estimated from data

  • priors Overview of priors implemented in bage

  • set_prior() Specify prior for intercept, main effect, or interaction

  • Mathematical Details vignette

Examples

N()
#>   N() 
#>          s: 1
N(s = 0.5)
#>   N(s=0.5) 
#>          s: 0.5