ch27.md

Chapter 27 - Exercises - R for Data Science

Francisco Yira Albornoz February 9th, 2019

• 27.3 Text formatting with R Markdown
  • 27.3.1 Exercises
• 27.4 Code chunks
  • 27.4.7 Exercises

27.3 Text formatting with R Markdown

27.3.1 Exercises

2. Using the R Markdown quick reference, figure out how to:

   1. Add a footnote.
   2. Add a horizontal rule.
   3. Add a block quote.

This is a block quote

---

This is a horizontal rule

This is a footnote ¹

3. Copy and paste the contents of diamond-sizes.Rmd from https://github.com/hadley/r4ds/tree/master/rmarkdown in to a local R markdown document. Check that you can run it, then add text after the frequency polygon that describes its most striking features.

27.4 Code chunks

27.4.7 Exercises

(answers in diamond-sizes.Rmd inside this repo)

1. Add a section that explores how diamond sizes vary by cut, colour, and clarity. Assume you’re writing a report for someone who doesn’t know R, and instead of setting echo = FALSE on each chunk, set a global option.

2. Add a section that describes the largest 20 diamonds, including a table that displays their most important attributes.

3. Modify diamonds-sizes.Rmd to use comma() to produce nicely formatted output. Also include the percentage of diamonds that are larger than 2.5 carats.

4. Set up a network of chunks where d depends on c and b, and both b and c depend on a. Have each chunk print lubridate::now(), set cache = TRUE, then verify your understanding of caching.

lubridate::now()

## [1] "2022-06-18 18:09:14 -04"

lubridate::now()

## [1] "2022-06-18 18:09:14 -04"

lubridate::now()

## [1] "2022-06-18 18:09:14 -04"

lubridate::now()

## [1] "2022-06-18 18:09:14 -04"

Footnotes

1. Here is the footnote. ↩