---
title: "Quarto Computations"
format:
  html:
    code-fold: true
---

```{r}
#| label: load-packages
#| echo: false

library(ggplot2)
```

There are `{r} nrow(mpg)` observations in our data.

```{r}
#| echo: false

mean_cty <- round(mean(mpg$cty), 2)
mean_hwy <- round(mean(mpg$hwy), 2)
```

The average city mileage of the cars in our data is `{r} mean_cty` and the average highway mileage is `{r} mean_hwy`.

The plots in @fig-mpg show the relationship between city and highway mileage for 38 popular models of cars.
In @fig-mpg-1 the points are colored by the number of cylinders while in @fig-mpg-2 the points are colored by engine displacement.

```{r}
#| label: fig-mpg
#| fig-cap: "City and highway mileage for 38 popular models of cars."
#| fig-subcap:
#|   - "Color by number of cylinders"
#|   - "Color by engine displacement, in liters"
#| layout-ncol: 2
#| column: page
#| cache: true

ggplot(mpg, aes(x = hwy, y = cty, color = cyl)) +
  geom_point(alpha = 0.5, size = 2) +
  scale_color_viridis_c() +
  theme_minimal()

ggplot(mpg, aes(x = hwy, y = cty, color = displ)) +
  geom_point(alpha = 0.5, size = 2) +
  scale_color_viridis_c(option = "E") +
  theme_minimal()
```