Getting_Started_with_Rmarkdown

Author

Nic Schwab

Open a new document

In the upper left:

choose R Markdown … (We’ll also use .qmd too)
choose html

The “?“

How to get more information on a dataset in R.

?mtcars

Load the tidyverse

What is the tidyverse?

Hit the little green c to add a chunk

library(tidyverse)

── Attaching packages ─────────────────────────────────────── tidyverse 1.3.2 ──
✔ ggplot2 3.3.6     ✔ purrr   0.3.4
✔ tibble  3.1.8     ✔ dplyr   1.0.9
✔ tidyr   1.2.0     ✔ stringr 1.4.0
✔ readr   2.1.2     ✔ forcats 0.5.1
── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag()    masks stats::lag()

view(mtcars)

Why do we load the tidyverse?

Let’s compare cylinders and gas mileage

mtcars |>
  ggplot(mapping = aes(mpg,cyl))+
  geom_point()

How can we make this graph clearer?

Let’s add another aesthetic, color:

mtcars |>
  ggplot(aes(mpg,cyl,color= am))+
  geom_point()

Let’s add a title and change the x and y axes labels.

mtcars |>
  ggplot(aes(mpg,cyl,color= factor(am)))+
  geom_point()+
  #scale_fill_brewer(palette = "blues") +
  labs(title = "Cylinders vs MPG",x="Miles Per Gallon",y="Cylinders")

Edit the legend

mtcars |>
  ggplot(aes(mpg,cyl,color= factor(am)))+
  geom_point()+
  scale_fill_brewer(palette = "YlOrRd") +
  scale_color_discrete(name="Transmission Type",
                      breaks=c("0","1"),
                      labels=c("automatic","manual"))+
  labs(title = "Cylinders vs MPG",x="Miles Per Gallon",y="Cylinders")

Let’s Facet a bit

mtcars |>
  ggplot(aes(mpg,color= factor(am)))+
  geom_boxplot()+
  facet_grid(rows=vars(cyl)) +
  scale_fill_brewer(palette = "YlOrRd") +
  scale_color_discrete(name="Transmission Type",
                      breaks=c("0","1"),
                      labels=c("automatic","manual"))+
  labs(title = "Cylinders vs MPG",x="Miles Per Gallon",y="Cylinders")