Class Array

  1. lib/stella/core_ext.rb
Parent: Object

Public class methods

from_json (str)
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# File lib/stella/core_ext.rb, line 443
  def self.from_json(str)
    Yajl::Parser.parse(str, :check_utf8 => false)
  end

Public instance methods

deviation ()
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# File lib/stella/core_ext.rb, line 413
  def deviation ; Math::sqrt( self.variance ) ; end
dump (format)
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# File lib/stella/core_ext.rb, line 436
  def dump(format)
    respond_to?(:"to_#{format}") ? send(:"to_#{format}") : raise("Unknown format: #{format}")
  end
histogram ()
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# File lib/stella/core_ext.rb, line 405
  def histogram ; self.sort.inject({}){|a,x|a[x]=a[x].to_i+1;a} ; end
mean ()
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# File lib/stella/core_ext.rb, line 398
  def mean; self.sum.to_f/self.size ; end
median ()
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# File lib/stella/core_ext.rb, line 399
  def median
    case self.size % 2
      when 0 then self.sort[self.size/2-1,2].mean
      when 1 then self.sort[self.size/2].to_f
    end if self.size > 0
  end
mode ()
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# File lib/stella/core_ext.rb, line 406
  def mode
    map = self.histogram
    max = map.values.max
    map.keys.select{|x|map[x]==max}
  end
percentile (perc)
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# File lib/stella/core_ext.rb, line 426
  def percentile(perc)
    self.sort[percentile_index(perc)]
  end
percentile_index (perc)
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# File lib/stella/core_ext.rb, line 429
  def percentile_index(perc)
    (perc * self.length).ceil - 1
  end
permute ()
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# File lib/stella/core_ext.rb, line 415
  def permute ; self.dup.permute! ; end
permute! ()
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# File lib/stella/core_ext.rb, line 416
  def permute!
    (1...self.size).each do |i| ; j=rand(i+1)
      self[i],self[j] = self[j],self[i] if i!=j
    end;self
  end
random ()
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# File lib/stella/core_ext.rb, line 423
  def random
    self[rand(self.size)]
  end
sample (n=1 ;)
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# File lib/stella/core_ext.rb, line 421
  def sample n=1 ; (0...n).collect{ self[rand(self.size)] } ; end
sd ()

Alias for deviation

squares ()
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# File lib/stella/core_ext.rb, line 411
  def squares ; self.inject(0){|a,x|x.square+a} ; end
sum ()
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# File lib/stella/core_ext.rb, line 397
  def sum ; self.inject(0){|a,x| next if x.nil? || a.nil?; x+a} ; end
to_json ()
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# File lib/stella/core_ext.rb, line 440
  def to_json
    Yajl::Encoder.encode(self)
  end
variance ()
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# File lib/stella/core_ext.rb, line 412
  def variance ; self.squares.to_f/self.size - self.mean.square; end