richfitz

## Empty list -- just use the empty environment for this.
nil <- function() {
  emptyenv()
}

## Test if a list is the empty list:
is_empty <- function(lis) {
  identical(lis, nil())
}

vsbuffalo

# A quick function to save a PBM (http://en.wikipedia.org/wiki/Netpbm_format)
# visualize *a lot* of missing data pretty quickly (outside of R).

writeMissingPBM <- function(x, file) {
  dims <- dim(x)
  x[] <- as.integer(is.na(x))
  con <- file(file, open="wt")
  writeLines(sprintf("P1\n%d %d", ncol(x), nrow(x)), con)
  write.table(x, file=con, sep=" ", col.names=FALSE, row.names=FALSE, quote=FALSE)
  close(con)

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!):

cscheid

# You should totally ignore this because it's the first piece of Julia I've ever written.
# 2-clause BSD, blah.

function make_cycle(n)
    result = Dict{Int32, Array{Int32}}()
    for i = 1:n
        ii = i - 1
        push!(result, i, [1 + ((i+n-2) % n), 1 + i % n])
    end
    result

kbroman

# convert c("female", "Male") to c(0,1)

# magrittr is way nicer than nested function calls

convert_sexcodes <-
function(codes)
{
    require(magrittr)

    tolower(codes) %>%

sckott

Elevation data

Using the Google Elevation API at the following link https://developers.google.com/maps/documentation/elevation/

Installation

jennybc

What if a function in a package has no examples? Or is poorly exampled? Wouldn't it be nice to find functioning instances of it "in the wild"?

Via Twitter, Noam Ross taught me a clever way to do such searches on GitHub. Put this into the GitHub search box to see people using the llply() function from plyr:

"llply" user:cran language:R

Or just click here.

barryrowlingson

### Colours of old Smarties with lovely artificial colouring, derived from:
###
###
### "Smarties old new" by John Penton and Paul Hughes - Own work. Licensed under CC BY-SA 2.5 via Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Smarties_old_new.jpg#mediaviewer/File:Smarties_old_new.jpg
###
### image was loaded into gimp, representative parts of each Smartie were isolated, the image converted to indexed palette
### with 9 colours, the palette then saved.
##
### "Smarties" is a trademark of Nestle
##

sckott

Playing with adding + operator for easily joining geojson objects together into a single valid geojson object. This is relatively easy with lists, but not so easy with json unless you speak json.

Get lawn package too for viewing data

devtools::install_github("ropensci/geojsonio")

hougs

Read

• Our Lady of Ruins, Barnard
• The Martian, Andy Weir (has good audiobook too) ++
• The Windup Girl, Paolo Bacigalupi
• Americanah, Chimamanda Ngozi Adichie +
• Swamplandia +
• Feynman, Jim Ottaviani
• Digger, Ursula Vernon