plot_normal_normal function

Plot a Normal-Normal Bayesian model

Consider a Normal-Normal Bayesian model for mean parameter $\mu$ with a N(mean, sd^2) prior on $\mu$ and a Normal likelihood for the data. Given information on the prior (mean and sd) and data (the sample size n, mean y_bar, and standard deviation sigma), this function produces a plot of any combination of the corresponding prior pdf, scaled likelihood function, and posterior pdf. All three are included by default.

plot_normal_normal(
  mean,
  sd,
  sigma = NULL,
  y_bar = NULL,
  n = NULL,
  prior = TRUE,
  likelihood = TRUE,
  posterior = TRUE
)

Arguments

• mean: mean of the Normal prior
• sd: standard deviation of the Normal prior
• sigma: standard deviation of the data, or likelihood standard deviation
• y_bar: sample mean of the data
• n: sample size of the data
• prior: a logical value indicating whether the prior model should be plotted
• likelihood: a logical value indicating whether the scaled likelihood should be plotted
• posterior: a logical value indicating whether posterior model should be plotted

Returns

a ggplot

Examples

plot_normal_normal(mean = 0, sd = 3, sigma= 4, y_bar = 5, n = 3)
plot_normal_normal(mean = 0, sd = 3, sigma= 4, y_bar = 5, n = 3, posterior = FALSE)