example of droopy densities

priors.Rmd

---
title: "Untitled"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```



```{r}
library(rstanarm)
library(tidybayes)

m1 <- stan_glm(mpg~wt, data=mtcars, prior_PD = FALSE)
m1.prior <- stan_glm(mpg~wt, data=mtcars, prior_PD = TRUE)

```

```{r}
preds <- add_fitted_samples(m1, newdata=tibble(wt=1))
preds.prior <- add_fitted_samples(m1.prior, newdata=tibble(wt=1))
```



```{r}
both <- bind_rows(preds %>% mutate(dist="posterior"), 
          preds.prior %>% mutate(dist="prior"))
```


```{r}
both %>% 
  ggplot(aes(estimate, color=dist)) + 
  geom_density() 
```


```{r}
both %>% 
  ggplot(aes(estimate, color=dist)) + 
  geom_density() +
  xlim(20,50)
```