Explore more RMarkdown functionality and practice implementing it.
Let’s start by playing around with the basic RStudio RMarkdown template a little more. Open a fresh copy by clicking File -> New File -> R Markdown… We can enter “Lab exercise” in the Title field and keep HTML as the Default Output Format.
Let’s play around with the formatting of our document. Remember that you can find RStudio’s built-in RMarkdown reference under Help > Markdown Quick Reference, or check out one of the many great cheatsheets you can find online, e.g. this or RStudio’s RMarkdown cheatsheet you can download from here (scroll down to find it).
As you’re making changes, knit often and see how your edits look in the rendered document.
Some ideas of what you can try:
Compare the output with different numbers of # in
headers
Add empty lines <br>
Another really cool and useful functionality is writing in-line code.
Code results can be inserted directly into the text of a .Rmd file by
enclosing the code with r. This way, you’re basically
running code inside a sentence. R Markdown will always display the
results of in-line code, but not the code, and apply relevant text
formatting to the results. As a result, inline output is
indistinguishable from the surrounding text, but will show up-to-date
results of your code.
We may for example want to summarize the dimensions of our dataset. We can do this by typing
There are `r nrow(cars)` observations in the cars dataset,
and `r ncol(cars)` variables.See how that renders.
In addition to figures generated through R code in our code chunks, it’s easy to also add other images, e.g. jpg or png files that you have stored on your computer or find online.
There are two ways we can do this:
knitr::include_graphics()The markdown syntax to insert an image is:
![caption]("path/to/image")
The path can either be a path to an image stored on your computer, or it can be a URL to an image stored online. If you want to get the URL to an image you find, right click and select “Copy Image Address”.
Using knitr::include_graphics(): If you want more control
over the output, e.g. to center the image or make it smaller, you can
use knitr::include_graphics(), and control the figure size
using options such as out.width and fig.align
and add a caption with fig.cap. More details here
You cannot align text with the native markdown syntex. However, depending on the output format, you can use other methods. For example, if you are knitting the RMarkdown file into an HTML file, you can use HTML tags such as the following:
<center> Centered text (HTML) </center>
[Aligned right (HTML)]{style="float:right"}Alternatively, if you are knitting the RMarkdown file into a PDF file, you can use LaTeX commands. E.g.,
\center Centered text (PDF) \center
\hfill Aligned right (PDF)Want to include equations in your writing? Easy. rmarkdown supports LaTeX style equation writing. We won’t go through this in class, but you can find an easy introduction in R Markdown for Scientists.
Remind yourself about the key code chunk options, see overview here
Add a few new code chunks to your document. Name them, add some simple code. Knit and see how the document renders.
Now try changing the code chunk options. Explore the settings to show code, show output, execute output vs not etc.
Now explore the first code chunk titled setup. What
happens if you change it to echo = FALSE? Or if you add
eval = FALSE? Why does this happen?
Add toc details to your YAML header
---
title: "Lab1_doc"
author: "Nina"
date: "2/12/2021"
output:
html_document:
toc: true
toc_depth: 2
---More details about styling your table of contents here
Up until now, we’ve been rendering our .Rmd file to the default html format. That’s useful for lots of applications. But lots of other output formats are supported.
Check what happens if you change the
output: html_document in the YAML header to
output: word_document
Now, check what happens if you change it to
output: pdf_document. In order to convert the documents to
PDF, they use a software called LaTeX (pronounced la-tek or
lay-tek).
Installing LaTeX can be a pain, but thankfully there is an easier way to install it - tinytex. tinytex is an R package that installs a sane, lightweight (<200Mb) version of LaTeX.
If you’re having trouble with the generating the pdf, see the note on
installing tinytex here.
We can also make slides! There are several slide output formats. Try
output: beamer_presentation
More details about styling beamer slides here
Now, practice what you’ve learned by creating a brief CV. The title should be your name, and you should include headings for (at least) education or employment. Each of the sections should include a bulleted list of jobs/degrees. Highlight the year in bold and add a footnote. You can also add a photo, either of yourself, or something else you have handy or can find online.
Render to html format, and if you’re comfortable, share with the
class by posting it to the lecture-chat channel in
Slack.
You will have seen how quickly you can create a nicely formatted document. But there are also lots of great CV templates out there that we can use. You could, for example, try one of these:
http://svmiller.com/blog/2016/03/svm-r-markdown-cv/ http://nickstrayer.me/datadrivencv/
RMarkdown can be used for much more than making simple documents. In small groups, explore examples of interactive documents, dashboards, books, websites, rticles, and more. You can find examples of all of these in the RStudio Gallery
Discuss in your groups which application you think is the coolest, and report back to the group.
END LAB 1