Utilities

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

gem install utilities

rspec

• 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+"]
  

• collect_first

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

• 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}
  

• raiser

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

• 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
  

• 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
  

• hour_to_float

    "14:30".hour_to_float #=> 14.5
  

• float?

    "123.456".float? #=> true
  

• 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
      }