jennybc

---
title: "Row bind a list of data.frames with a key"
author: "Jenny Bryan"
date: "22 August, 2014"
output:
  html_document:
    keep_md: TRUE
---

I posed a question on Twitter (click to see the figure!):

jennybc

```{r setup, include = FALSE, cache = FALSE}
knitr::opts_chunk$set(error = TRUE)
```

jennybc

#' ---
#' title: "Something fascinating"
#' author: "Jenny Bryan"
#' date: "`r format(Sys.Date())`"
#' output: github_document
#' ---

jennybc

Inspired by recent @johnmyleswhite tweets on indexing (though they focus more on NA stuff)

My standard advice to R novices is "don't worry about numeric vs integer too much, for now", but I just created an indexing example that scares me.

I did not realize it was sooo easy to create this gotcha when indexing with numeric (which I know is not a great idea).

jennybc

---
title: "Get verbatim R chunks in R Markdown"
author: "Jenny Bryan"
date: "18 September, 2014"
output:
  html_document:
    keep_md: TRUE
---

My periodic revisitation of "how can I include a verbatim R chunk in `.rmd`"? This time I am writing it down! Various proposed solutions:

jennybc

Demo errors in knitted doc vs. other

Jenny Bryan
29 September, 2014

Context: In a recent lesson, I claim (with some justification) that raising an error inside a function via if() ... stop() often gives more info than using stopifnot(). This is partly because you get to write your own error message. But also because you learn the name of the function that threw the error. Or so I thought.

Here's a toy function to generate an error.

jennybc

scale_x_discrete(limits = rev(levels(the_factor)))

jennybc

There are packages for this now!

2017-08-03: Since I wrote this in 2014, the universe, specifically Kirill Müller (https://github.com/krlmlr), has provided better solutions to this problem. I now recommend that you use one of these two packages:

• rprojroot: This is the main package with functions to help you express paths in a way that will "just work" when developing interactively in an RStudio Project and when you render your file.
• here: A lightweight wrapper around rprojroot that anticipates the most likely scenario: you want to write paths relative to the top-level directory, defined as an RStudio project or Git repo. TRY THIS FIRST.

I love these packages so much I wrote an ode to here.

I use these packages now instead of what I describe below. I'll leave this gist up for historical interest. 😆

jennybc

suppressPackageStartupMessages(library(dplyr))

Get word counts for Character * Chapter in LOTR trilogy

if(!file.exists("lotr_clean.tsv")) {
  download.file(paste0("https://raw.githubusercontent.com/jennybc/",
 "lotr/master/lotr_clean.tsv"), 

jennybc

## 2015-11-11 NOTE!
## with_libpaths() is one of the functions removed (well, deprecated, for now) from
## devtools
## it's in withr now!
## see newer script below!!!

library(devtools) # with_lib(), install_github()

tmp_lib <- "~/tmp/tmp_lib"
dir.create(tmp_lib)