# Formatting

## Front matter

The front matter at the top of the Markdown document has the following format and fields (the same for plain and R-flavoured Markdown):

---
title: "Useful one-function R packages, big data solutions, and a message from Yoda"
authors: ["Eduardo García-Portugués"]
date: 2018-05-10
categories: ["R"]
tags: ["R", "big data", "visualization", "benchmark"]
---


The selected categories should be the main high-level languages or technologies used in the tutorial (see the current list of categories). The selected tags should be the categories plus any fundamental concept covered in the tutorial (see the current list of tags).

Additionally, if you are editing in R Markdown, the following code chunk should be placed right after the front matter:

{r, setup, include = FALSE}
knitr::opts_chunk$set(echo = TRUE)   Finally, the first paragraph or your document, after the front matter, must be the abstract, without any leading title. Example: As the title reads, in this heterogeneous session we will see three topics of different interest. The first is a collection of three simple and useful one-function R packages that I use regularly in my coding workflow. The second collects some approaches to handling and performing linear regression with big data. The third brings in the freaky component: it presents tools to display graphical information in plain ASCII, from bivariate contours to messages from Yoda!  ## Writing guidelines In Markdown, you can write rich text, you can include code, images… and of course, math! For general guidelines, please refer to the theme’s documentation: Writing content with Markdown,$\LaTeX\$, and Shortcodes. In the following, there are some comments about the style.

Top-level headings (<h1>) shall not be used, because this is the format in which the title of the post is rendered. Only sub-headings shall be used, and using more than three levels is not advisable. Also please add space before and after any sub-heading:

## Sub-heading 2

Some text...

Some text...

Some text...



### Lists

Dashes are preferred over asterisks for unordered lists, because asterisks are also used for emphasize words and may cause issues. To properly render lists, please remove any empty lines between list elements:

1. one element
- one thing
- another thing
2. second element


### Images

If you use the general Markdown shortcode to include images (![alt](path)), the path must be relative to /static/:

![<alt text here>](/post/<date>_files/<image-name>)


## Tips and tricks

• It is advisable to provide a list of required packages at the beginning, right after the abstract (“this tutorial requires the following packages…”), along with the command(s) required to install them (set the option eval=FALSE for that chunk to avoid its execution during rendering).
• Keep the rendering time low. If any chunk takes a lot of time, prevent its execution by setting the option eval=FALSE in that particular chunk. If the result is important (e.g., a plot) execute it once and save the result as a static resource.
• If your tutorial requires any non-trivial piece of software (e.g., Tensorflow, Stan…), it is better to provide a .md, or to set eval=FALSE as a global option in the setup chunk, at the top of your .Rmd.