photomattmills

# Current debian stable for our base.
FROM debian:jessie
ENV LANG C.UTF-8

# Install base package, plus some Erlang deps
RUN apt-get update
RUN apt-get install -y wget git build-essential libwxbase3.0-0 libwxgtk3.0-0

# Install Erlang. This package is the current stable.

photomattmills

auspost = { #table containing all the alphanumeric codes for auspost barcodes
  "222" => "0",
  "300" => "1",
  "301" => "2",
  "302" => "3",
  "310" => "4",
  "311" => "5",
  "312" => "6",
  "320" => "7",
  "321" => "8",

photomattmills

I was looking at Facebook's 'this day in your timeline' thingy when I came across this tweet that I'd retweeted way back in prehistory: https://twitter.com/dbrady/status/12546255974 . It contains a one-liner that prints an ASCII mandelbrot set: 60.times{|a|puts((0..240).map{|b|x=y=i=0;until(x*x+y*y>4||i==99);x,y,i=x*x-y*y+b/120.0-1.5,2*x*y+a/30.0-1,i+1;end;i==99?'#':'.'}*'');}

I wanted to understand it, so the first thing I did was unfold all the blocks, and turn the multiple assignment into three separate lines:

60.times do |a|
  puts((0..240).map do |b|
    x=y=i=0
    until(x*x+y*y>4||i==99)
      x = x*x-y*y+b/120.0-1.5

photomattmills

# BUCKET = ::AWS::S3::Bucket.new(AWS_CONFIG["medium_bucket"])
#
# derivatives = Derivative.where(label: 'high_res_proxy_mp4', upload_complete: nil)
#
# derivatives.inject([]) do |array, derivative|
#   s3_file = BUCKET.objects[derivative.file_path] rescue nil
#   if s3_file && s3_file.exists? && s3_file.content_length == derivative.file_size
#     array << derivative
#   end
#   array

photomattmills

http://www.erlang-in-anger.com/

http://learnyousomeerlang.com/content

photomattmills

require 'faraday'
require 'json'

class Temp
  def temp_request
    @temp_request ||= Faraday.post('https://api.spark.io/v1/devices/51ff70065067545733280187/analogread', {
      access_token: '',
      params: 'A0'
    })
  end

photomattmills

class Phrase
  def initialize(words)
    @words = words
  end
  
  def word_count
    @words.downcase.scan(/\w+/).inject(Hash.new(0)) { |list,word| list.merge!({ word => list[word]+1 }) }
  end
end

photomattmills

#this uses /usr/share/dict/words, which isn't terribly compatible with letterpress. This is just a proof of concept, please don't cheat. Also, it's fairly slow; there's probably a better way to exclude things quickly.

def list_words(letters, length)
  words = File.read("/usr/share/dict/words").split "\n"
  word_arrays = words.map{|word| word.downcase.split("") }
  accepted_word_arrays = word_arrays.select{|word_array| check_word(word_array, letters, length)}
  words = accepted_word_arrays.map{|word_array| word_array.join("") }.compact
  words.select!{|word| word.length >= length }
  words.sort!{|wa,wb| wa.length <=> wb.length }
end  

photomattmills

class Dir
  def map(&block)
    output = []
    self.each do |entry|
      output << block.call(entry)
    end
    return output 
  end
  
  def select(&block)

photomattmills

So this is a fast way to test primality of a number, called a sieve. The PRIMES constant is a list of all the prime numbers below sqrt(1000000000). Computing the values in the sieve actually takes a relatively long time, on the order of seconds; someone cleverer than me could probably make it recursive, such that it would construct itself on the fly, but all of my attempts to do this took much longer than a constant.

Also, protip, don't do expensive calculations like sqrt(n) more than once if you can avoid it. That actually was a huge performance gain, the reason this is an order of magnitude (or more) faster and not just 70% faster.