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Returns a summary of the priors used in the model.

Usage

describe_prior(model, ...)

# S3 method for class 'brmsfit'
describe_prior(model, parameters = NULL, ...)

Arguments

model

A Bayesian model.

...

Currently not used.

parameters

Regular expression pattern that describes the parameters that should be returned. Meta-parameters (like lp__ or prior_) are filtered by default, so only parameters that typically appear in the summary() are returned. Use parameters to select specific parameters for the output.

Examples

# \donttest{
library(bayestestR)

# rstanarm models
# -----------------------------------------------
if (require("rstanarm")) {
  model <- rstanarm::stan_glm(mpg ~ wt + cyl, data = mtcars)
  describe_prior(model)
}
#> 
#> SAMPLING FOR MODEL 'continuous' NOW (CHAIN 1).
#> Chain 1: 
#> Chain 1: Gradient evaluation took 2e-05 seconds
#> Chain 1: 1000 transitions using 10 leapfrog steps per transition would take 0.2 seconds.
#> Chain 1: Adjust your expectations accordingly!
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#> Chain 1:                0.093 seconds (Total)
#> Chain 1: 
#> 
#> SAMPLING FOR MODEL 'continuous' NOW (CHAIN 2).
#> Chain 2: 
#> Chain 2: Gradient evaluation took 1.1e-05 seconds
#> Chain 2: 1000 transitions using 10 leapfrog steps per transition would take 0.11 seconds.
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#> 
#> SAMPLING FOR MODEL 'continuous' NOW (CHAIN 3).
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#> Chain 3: Gradient evaluation took 3.5e-05 seconds
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#> 
#> SAMPLING FOR MODEL 'continuous' NOW (CHAIN 4).
#> Chain 4: 
#> Chain 4: Gradient evaluation took 1.1e-05 seconds
#> Chain 4: 1000 transitions using 10 leapfrog steps per transition would take 0.11 seconds.
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#> Chain 4:  Elapsed Time: 0.058 seconds (Warm-up)
#> Chain 4:                0.042 seconds (Sampling)
#> Chain 4:                0.1 seconds (Total)
#> Chain 4: 
#>     Parameter Prior_Distribution Prior_Location Prior_Scale
#> 1 (Intercept)             normal       20.09062   15.067370
#> 2          wt             normal        0.00000   15.399106
#> 3         cyl             normal        0.00000    8.436748

# brms models
# -----------------------------------------------
if (require("brms")) {
  model <- brms::brm(mpg ~ wt + cyl, data = mtcars)
  describe_prior(model)
}
#> Compiling Stan program...
#> Start sampling
#> 
#> SAMPLING FOR MODEL 'anon_model' NOW (CHAIN 1).
#> Chain 1: 
#> Chain 1: Gradient evaluation took 9e-06 seconds
#> Chain 1: 1000 transitions using 10 leapfrog steps per transition would take 0.09 seconds.
#> Chain 1: Adjust your expectations accordingly!
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#> Chain 1:                0.035 seconds (Total)
#> Chain 1: 
#> 
#> SAMPLING FOR MODEL 'anon_model' NOW (CHAIN 2).
#> Chain 2: 
#> Chain 2: Gradient evaluation took 3e-06 seconds
#> Chain 2: 1000 transitions using 10 leapfrog steps per transition would take 0.03 seconds.
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#> SAMPLING FOR MODEL 'anon_model' NOW (CHAIN 3).
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#> 
#> SAMPLING FOR MODEL 'anon_model' NOW (CHAIN 4).
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#> Chain 4: Gradient evaluation took 3e-06 seconds
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#> Chain 4:  Elapsed Time: 0.02 seconds (Warm-up)
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#> Chain 4: 
#>     Parameter Prior_Distribution Prior_Location Prior_Scale Prior_df
#> 1 b_Intercept          student_t           19.2         5.4        3
#> 2        b_wt            uniform             NA          NA       NA
#> 3       b_cyl            uniform             NA          NA       NA
#> 4       sigma          student_t            0.0         5.4        3

# BayesFactor objects
# -----------------------------------------------
if (require("BayesFactor")) {
  bf <- ttestBF(x = rnorm(100, 1, 1))
  describe_prior(bf)
}
#>    Parameter Prior_Distribution Prior_Location Prior_Scale
#> 1 Difference             cauchy              0   0.7071068
# }