Chapter 2 Applications

Some significant applications are demonstrated in this chapter.

2.1 Example one

2.2 Example two

library(tidyverse)

## ── Attaching packages ─────────────────────────────────────────────────────────────────────────── tidyverse 1.2.1 ──

## ✔ ggplot2 3.2.0     ✔ purrr   0.3.2
## ✔ tibble  2.1.3     ✔ dplyr   0.8.3
## ✔ tidyr   0.8.3     ✔ stringr 1.4.0
## ✔ readr   1.3.1     ✔ forcats 0.4.0

## ── Conflicts ────────────────────────────────────────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ dplyr::filter() masks stats::filter()
## ✖ dplyr::lag()    masks stats::lag()

starwars %>% 
  count(homeworld, sort = TRUE)

## # A tibble: 49 x 2
##    homeworld     n
##    <chr>     <int>
##  1 Naboo        11
##  2 Tatooine     10
##  3 <NA>         10
##  4 Alderaan      3
##  5 Coruscant     3
##  6 Kamino        3
##  7 Corellia      2
##  8 Kashyyyk      2
##  9 Mirial        2
## 10 Ryloth        2
## # … with 39 more rows

library(tidyverse)
starwars %>% 
  count(homeworld, sort = TRUE)
#> # A tibble: 49 x 2
#>    homeworld     n
#>    <chr>     <int>
#>  1 Naboo        11
#>  2 Tatooine     10
#>  3 <NA>         10
#>  4 Alderaan      3
#>  5 Coruscant     3
#>  6 Kamino        3
#>  7 Corellia      2
#>  8 Kashyyyk      2
#>  9 Mirial        2
#> 10 Ryloth        2
#> # … with 39 more rows

Our setup code chunk above affects all code chunks. It is called a global chunk option for that reason. You can (and should) use individual chunk options too, but setting up some nice ones that apply to all code chunks can save you time and can lessen your cognitive load as you create your content.

2.3 Two plots side-by-side

ggplot(mtcars, aes(factor(cyl), fill = factor(vs))) +
  geom_bar(position = position_dodge(preserve = "total"))

ggplot(mtcars, aes(factor(cyl), fill = factor(vs))) +
  geom_bar(position = position_dodge2(preserve = "total"))

2.4 Include verbatim code chunks

You may have noticed that the code chunk output, even when echo=TRUE, does not show the actual code chunk options that you see in your .Rmd file. In order to print the full code chunk, you’ll need to

• verbatim code chunks

• knitr ref.label to reuse code chunks
• the fig.path thing: https://yihui.name/knitr/options/#plots (see also: name your code chunks!)
• making sure that your package warnings/messages don’t print!
• how to control numbers of digits that print

• control significance stars

options(
  show.signif.stars = FALSE,     
  digits = 2
  )