Scott Stanfield scottstanfield

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

agnoster.zsh-theme

A ZSH theme optimized for people who use:

Solarized
Git
Unicode-compatible fonts and terminals (I use iTerm2 + Menlo)

For Mac users, I highly recommend iTerm 2 + Solarized Dark

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD

	#!/bin/sh

	###
	# SOME COMMANDS WILL NOT WORK ON macOS (Sierra or newer)
	# For Sierra or newer, see https://github.com/mathiasbynens/dotfiles/blob/master/.macos
	###

	# Alot of these configs have been taken from the various places
	# on the web, most from here
	# https://github.com/mathiasbynens/dotfiles/blob/5b3c8418ed42d93af2e647dc9d122f25cc034871/.osx

	## Load libraries
	library(mclogit)
	library(reshape)
	library(rjags)
	library(R2WinBUGS) ## for write.model

	## Load the data file from mclogit
	data(Transport)

	## Do the mclogit model

	library(shiny)
	library(PerformanceAnalytics)
	data(managers)


	# Define server logic required to plot relative performance
	shinyServer(function(input, output) {

	# Use charts.PerformanceSummary from Performance Analytics package
	# to generate a performance summary plot

	# This file has a set of extra tests, expectations and structures extending
	# the excellent testthat package[1].
	#
	# I suggest you read Hadley's introductory article[2] to become acquainted
	# with testthat.
	#
	# THIS IS NOT A POLISHED PRODUCT.
	#
	# Helpful functions provided
	# - describe : almost the same as a context, for grouping tests

	#
	# Working with branches
	#

	# Get the current branch name (not so useful in itself, but used in
	# other aliases)
	branch-name = "!git rev-parse --abbrev-ref HEAD"
	# Push the current branch to the remote "origin", and set it to track
	# the upstream branch
	publish = "!git push -u origin $(git branch-name)"