citizen428

require 'tweetstream'
require 'rtranslate'
 
TweetStream::Client.new('username','password').track('keyword') do |status|
  puts Translate.t(status[:text], 'en', 'de')
end

citizen428

db = Connection.new(ENV['DATABASE_URL']).db(db_name)
if ENV['DATABASE_USER'] && ENV['DATABASE_PASSWORD']
  auth = db.authenticate(ENV['DATABASE_USER'], ENV['DATABASE_PASSWORD'])
end

citizen428

class Polynomial
  def initialize(coefficients)
    raise ArgumentError, "Need at least 2 coefficients" if coefficients.size < 2 
    @co = coefficients
    @powers = Array.new(@co.size - 2) { |i| "x^#{i+2}"}.reverse << 'x' << nil
  end

  def to_s
    return "0" if @co.all? { |c| c.zero? } # not much to do in this case
    @co.zip(@powers).map do |el| 

citizen428

class Lucky < [String, Array][rand(2)]; end
puts Lucky.superclass

citizen428

Usage: clj [java-opt*] [init-opt*] [main-opt] [arg*]

  With no options or args, runs an interactive Read-Eval-Print Loop

  java options:
    -<javaopt>        Configure JVM (see `java -help` for full list)
    -d, --debug port  Open a port for debugging

  init options:
    -i, --init path   Load a file or resource

citizen428

Cloud Providers

• Amazon Web Services
• Elastic Server
• Eucalyptus
• GoGrid
• Google App Engine
• Linode - Xen VPS Hosting
• Microsoft Azure

citizen428

(use '(incanter core charts io))
(def usage (read-dataset "report.csv" :header true))

(def instance-types
     (set (filter #(re-find #"BoxUsage" %) ($ :UsageType usage))))

(with-data (->> ($rollup :sum :UsageValue :UsageType usage)
                ($where {:UsageType {:$in instance-types}}))
  (view (bar-chart :UsageType :UsageValue
                   :title "EC Instance Usage"

citizen428

user=> ; generate random number
user=> (rand)
0.8545074632292601
user=> ; infinite list of random numbers
user=> ; make sure to set *print-length*
user=> (set! *print-length* 10)
10
user=> (repeatedly rand)
(0.13569783475252373 0.585868618595554 0.7048671603900427 0.1440943435265447 0.24546858003727567 0.15406959135696596 0.41117257771529947 0.1115848319639422 0.669215744258339 0.1521494621978804 ...)
user=> ; get the reductions function from seq-utils

citizen428

class Fixnum
  alias_method :intdiv, :/
  
  def /(divisor)
    (self % divisor) == 0 ? self.intdiv(divisor) : self.to_f/divisor
  end
end

citizen428

user=> ; get the expt funtion
user=> (use '[clojure.contrib.math :only (expt)])
nil
user=> (expt 2 3)
8
user=> ; function to calculate no. of pairs for n people
user=> (defn number-pairs [n] (/ (* n (- n 1)) 2))
#'user/number-pairs
user=> ; how many pairs for 23 people?
user=> (number-pairs 23)