colored-math.Rmd

---
title: "Coloring stuff!"
author: "Andrew Heiss"
date: "`r Sys.Date()`"
output:
  xaringan::moon_reader:
    lib_dir: "libs"
    seal: false  # No title slide
    nature:
      highlightStyle: github
      highlightLines: true
      countIncrementalSlides: false
      ratio: "16:9"
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(warning = FALSE, message = FALSE, 
                      fig.retina = 3, fig.align = "center")
```

```{r load-libraries, include=FALSE}
library(tidyverse)
library(flair)
library(ggdag)
```

# DAGs and models

```{r mpg-dag, echo=FALSE, fig.width=5, fig.height=3.5, out.width="40%"}
mpg_dag <- dagify(hwy ~ drv + disp + cyl,
                  disp ~ drv + cyl,
                  labels = c("hwy" = "Highway MPG",
                             "drv" = "Drive",
                             "disp" = "Displacement",
                             "cyl" = "Cylinders"),
                  coords = list(x = c(hwy = 3, drv = 2, disp = 2, cyl = 1),
                                y = c(hwy = 2, drv = 1, disp = 3, cyl = 2))) %>% 
  tidy_dagitty()
  
ggplot(mpg_dag, aes(x = x, y = y, xend = xend, yend = yend)) + 
  geom_dag_edges() +
  geom_dag_point(aes(color = label)) +
  geom_dag_label_repel(aes(label = label, fill = label), seed = 1234,
                       direction = "y", fontface = "bold", color = "white") +
  scale_fill_manual(values = c("#39CCCC", "#2ECC40", "#0074D9", "#FF851B")) +
  scale_color_manual(values = c("#39CCCC", "#2ECC40", "#0074D9", "#FF851B")) +
  guides(color = FALSE, fill = FALSE) +
  theme_dag()
```



.pull-left[
```{r example-model, include=FALSE, eval=FALSE}
model <- lm(hwy ~ drv + displ + cyl, 
            data = mpg)
```

```{r colored-model, echo=FALSE}
decorate("example-model") %>% 
  flair("hwy", color = "#FF851B") %>% 
  flair("drv", color = "#0074D9") %>% 
  flair("displ", color = "#2ECC40") %>% 
  flair("cyl", color = "#39CCCC")
```
]

.pull-right[
$$
\begin{aligned}
\color{#FF851B}{\text{Highway MPG }} =\ & \beta_0 + \beta_1 \color{#0074D9}{\text{Drive}} + \\
&\beta_2 \color{#2ECC40}{\text{Displacement}} + \\
&\beta_3 \color{#39CCCC}{\text{Cylinders}} + \varepsilon
\end{aligned}
$$
]