example-data: Example draws to use in demonstrations and tests

In bayesplot: Plotting for Bayesian Models

Example draws to use in demonstrations and tests

Description

These functions return various objects containing data used in the examples throughout the bayesplot package documentation.

Usage

example_mcmc_draws(chains = 4, params = 4)

example_yrep_draws()

example_y_data()

example_x_data()

example_group_data()

Arguments

chains	An integer between 1 and 4 indicating the desired number of chains.
params	An integer between 1 and 6 indicating the desired number of parameters.

Details

Each of these functions returns an object containing data, parameter draws, or predictions corresponding to a basic linear regression model with data y (outcome vector) and X (predictor matrix), and parameters alpha (intercept), beta (coefficient vector), and sigma (error sd).

example_mcmc_draws()

If chains > 1, a 250 (iterations) by chains by params array or, if chains = 1, a 250 by params matrix of MCMC draws from the posterior distribution of the parameters in the linear regression model described above. If params = 1 then only the draws for alpha are included in the returned object. If params >= 2 then draws for sigma are also included. And if params is between 3 and the maximum of 6 then draws for regression coefficients beta[k] (k in 1:(params-2)) are also included.

example_y_data()

A numeric vector with 434 observations of the outcome variable in the linear regression model.

example_x_data()

A numeric vector with 434 observations of one of the predictor variables in the linear regression model.

example_group_data()

A factor variable with 434 observations of a grouping variable with two levels.

example_yrep_draws()

A 500 (draws) by 434 (data points) matrix of draws from the posterior predictive distribution. Each row represents a full dataset drawn from the posterior predictive distribution of the outcome y after fitting the linear regression model mentioned above.

Value

See Details.

Examples

draws <- example_mcmc_draws()
dim(draws)
dimnames(draws)

draws <- example_mcmc_draws(1, 2)
dim(draws)
colnames(draws)

draws <- example_mcmc_draws(params = 6)
dimnames(draws)[[3]]

y <- example_y_data()
x <- example_x_data()
group <- example_group_data()
length(y)
length(x)
length(group)
tail(data.frame(y, x, group), 5)

yrep <- example_yrep_draws()
dim(yrep) # ncol(yrep) = length(y) = length(x) = length(group)

bayesplot documentation built on May 29, 2024, 2:27 a.m.