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. 😆

clhenrick

PostgreSQL & PostGIS Cheatsheet

This is a collection of information on PostgreSQL and PostGIS for what I tend to use most often.

TOC

• Installing Postgres & PostGIS
• Using Postgres on the command line: PSQL
• Importing Data into Postgres
• Exporting Data from Postgres
• Joining Tables

kevinushey

enumerate <- function(X, FUN, ...) {
  result <- vector("list", length(X))
  for (i in seq_along(result)) {
    tmp <- FUN(X[[i]], i, ...)
    if (is.null(tmp))
      result[i] <- list(NULL)
    else
      result[[i]] <- tmp
  }
  result

crazyhottommy

#linux commands basics
#http://software-carpentry.org/v5/novice/shell/index.html
# practise, practise, practise, google, google, google and you will get it :)

pwd  # print working directory
cd   # change directory
sudo  # super user privilege
chmod 775 # change the privileges  http://en.wikipedia.org/wiki/Chmod
git clone # version control! get to know git and github! http://git-scm.com/ 
sudo bash  # bad habit

gavinsimpson

`derivSimulCI` <- function(mod, n = 200, eps = 1e-7, newdata, term,
                           samples = 10000) {
    stopifnot(require("MASS"))
    if(inherits(mod, "gamm"))
        mod <- mod$gam
    m.terms <- attr(terms(mod), "term.labels")
    if(missing(newdata)) {
        newD <- sapply(model.frame(mod)[, m.terms, drop = FALSE],
                       function(x) seq(min(x), max(x) - (2*eps), length = n))
        names(newD) <- m.terms

Kartones

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

ecasilla

##
# Creates an alias called "git hist" that outputs a nicely formatted git log.
# Usage is just like "git log"
# Examples:
#   git hist
#   git hist -5
#   git hist <branch_name>
#   git hist <tag_name> -10
##
git config --global alias.hist "log --pretty=format:'%C(yellow)[%ad]%C(reset) %C(green)[%h]%C(reset) | %C(red)%s %C(bold red){{%an}}%C(reset) %C(blue)%d%C(reset)' --graph --date=short"

lelandbatey

Description

This simple script will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.

The script is here:

#!/bin/bash
convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2"

Results

ateucher

require(ggplot2)

set.seed(42)

df <- data.frame(x=1:50, y=rnorm(50, 10, 2), int=rbinom(50,1,0.3))

ggplot(df, aes(x=x, y=y)) +
  geom_ribbon(aes(ymin=0, ymax=y, fill='#1E90FF'), alpha=0.3) +
  geom_abline(intercept=10, slope=-0.1
              , aes(colour='Linear')) +

hrbrmstr

notify <- function(msg="Operation complete") {

  in.osx <- (Sys.info()['sysname'] == "Darwin")
  in.rstudio <- (Sys.getenv("RSTUDIO") == "1")
  in.rgui <- (Sys.getenv("R_GUI_APP_REVISION") != "")
  
  if (in.rstudio) { # hack to see if running in RStudio
    title <- "RStudio"
    sender <- activate <- "org.rstudio.RStudio"
  }