index.qmd

---
title: "Code annotation"
format: html
editor: visual
toc: true
code-annotations: hover
---

Sometimes you want to add some context to your code, without cluttering the code chunk.

This is totally doable. Just add `# <1>` next to the code line to attach an annotation to it, and define the annotation below the code chunk.

In the code below, try to hover over the numbers on the right!

```{r, warning=F, message=F}
# Load dplyr package
library(dplyr) # <1>

mtcars_summary <- mtcars %>%
  filter(cyl == 6) %>% 
  select(mpg, hp, wt) %>%
  summarise(
    avg_mpg = mean(mpg), # <2>
    avg_hp = mean(hp),# <2>
    avg_wt = mean(wt)# <2>
  )
```

1. `dplyr` is one of the cornerstone of the tidyverse, really useful for data wrangling.
2. here I'm computing 3 variables, the averages of `mpg`, `hp` and `wt`