Utilities

Utilities provides a handful of useful goodies including statistics, numeric arrays and the well-known raiser.

Installation

gem install utilities

Test

rspec test/test_utilities

Usage

Array

• to_numerics

  ["3", 4, "7.9"].to_numerics #=> [3.0, 4.0, 7.9]
  

• numerics?

  [1, 2.0, 3].numerics? #=> true
  

• reverse_sort

  [1,8,3].reverse_sort #=> [8,3,1]
  

• map_with

  [1,2,3].map_with([4,5,6]){|i,j| i * j }  #=> [4,10,18]
  

• wrap

  [1, 2, 3].wrap("*") #=> ["*1*", "*2*", "*3*"]
  [1, 2, 3].wrap("*", "+") #=> ["*1+", "*2+", "*3+"]
  

Enumerable

• collect_first

  {:a=>1, :b=>2, :c=>3}.collect_first{|k,v| [k, v * 3] if v == 2 } #=> [:b, 6]
  

Hash

• collect_keys, map_keys (passing true as a parameter will collect keys recursively)

  {:a=>1, :b=>2, :c=>3}.collect_keys{|k| k.to_s.upcase } #=> {"A"=>1, "B"=>2, "C"=>3}
  

• collect_values, map_values (passing true as a parameter will collect values recursively)

  {:a=>1, :b=>2, :c=>3}.collect_values{|v| v * -1 } #=> {:a=>-1, :b=>-2, :c=>-3}
  

• symbolize_keys

  {"a"=>1, "b"=>2}.symbolize_keys #=> {:a=>1, :b=>2}
  

• stringify_keys

  {:a=>1, :b=>2}.stringify_keys #=> {"a"=>1, "b"=>2}
  

Kernel

• raiser

  raiser 1, Hash.new, Array.new #=> RuntimeError "1, {}, []"
  

Numeric

• degrees

  180.degrees == Math::PI #=> true
  

• square

  2.square #=> 4
  

• hour_to_string

  14.5.hour_to_string #=> "14:30"
  

• sqrt

  9.sqrt #=> 3
  

• rank

  5.rank(3, 9) #=> 0.3333...
  

• to_decimals

  1.759.to_decimals(2) #=> 1.76
  

• percentage_of

  48.percentage_of(50) #=> 96
  

Object

• attempt

  Attempts to call a method on given object. If it fails (nil or NoMethodError), returns nil

  nil.attempt(:something) #=> nil
  "String".attempt(:wrong_method_name) #=> nil
  

• is_any?

  Returns true if object is one of the passed classes

  {}.is_any?(Array, Hash, Class) #=> true
  "".is_any?(Array) #=> false
  

String

• hour_to_float

  "14:30".hour_to_float #=> 14.5
  

• float?

  "123.456".float? #=> true
  

Utilities

• Statistics

  This module is intended to provide basic statistic functionnalities to numeric arrays. You may either call [].to_stats or extend an existing array with Utilities::Statistics module.

  • sum

    [1,2,3].sum #=> 6
    

  • squares

    [1,2,3].squares #=> [1,4,9]
    

  • sqrts

    [9,16,25].sqrts #=> [3,4,5]
    

  • mean

    [1,2,3,4,5].mean #=> 3
    

  • frequences

    [1,1,2,3,3,3,4].frequences #=> {1=>2, 2=>1, 3=>3, 4=>1}
    

  • modes

    [1,2,3,3,4,4,4,5].modes #=> {4=>3}
    

  • statistics

    [1,2,3,4,5].statistics #=> {
      :first=>1,
      :last=>5,
      :size=>5,
      :sum=>15,
      :squares=>[1, 4, 9, 16, 25],
      :sqrts=>[1.0, 1.4142135623730951, 1.7320508075688772, 2.0, 2.23606797749979],
      :min=>1,
      :max=>5,
      :mean=>3.0,
      :frequences=>{1=>1, 2=>1, 3=>1, 4=>1, 5=>1},
      :variance=>2.5,
      :standard_deviation=>1.5811388300841898,
      :population_variance=>2.0,
      :population_standard_deviation=>1.4142135623730951,
      :modes=>{1=>1, 2=>1, 3=>1, 4=>1, 5=>1},
      :ranks=>[0.0, 1.0, 2.0, 3.0, 4.0],
      :median=>3,
      :midrange=>3.0,
      :statistical_range=>4,
      :quartiles=>[1.5, 3, 4.5],
      :interquartile_range=>3.0
    }