Class: Statsample::Test::T::OneSample

Inherits:
Object
  • Object
show all
Includes:
DirtyMemoize, Math, Statsample::Test
Defined in:
lib/statsample/test/t.rb

Overview

One Sample t-test

Usage

a=1000.times.map {rand(100)}.to_scale
t_1=Statsample::Test::T::OneSample.new(a, {:u=>50})
t_1.summary

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Statsample::Test

chi_square, levene, #p_using_cdf, t_one_sample, t_two_samples_independent, u_mannwhitney

Constructor Details

#initialize(vector, opts = Hash.new) ⇒ OneSample

Returns a new instance of OneSample.



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# File 'lib/statsample/test/t.rb', line 80

def initialize(vector, opts=Hash.new)
  @vector=vector
  default={:u=>0, :name=>"One Sample T Test", :tails=>:both}
  @opts=default.merge(opts)
  @name=@opts[:name]
  @u=@opts[:u]
  @tails=@opts[:tails]
  @df= @vector.n_valid-1
  @t=nil
end

Instance Attribute Details

#df ⇒ Object (readonly)

Degress of freedom



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# File 'lib/statsample/test/t.rb', line 69

def df
  @df
end

#name ⇒ Object

Name of test



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# File 'lib/statsample/test/t.rb', line 65

def name
  @name
end

#opts ⇒ Object

Options



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# File 'lib/statsample/test/t.rb', line 63

def opts
  @opts
end

#probability ⇒ Object (readonly)

Probability



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# File 'lib/statsample/test/t.rb', line 73

def probability
  @probability
end

#t ⇒ Object (readonly)

Value of t



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# File 'lib/statsample/test/t.rb', line 71

def t
  @t
end

#tails ⇒ Object

Tails for probability (:both, :left or :right)



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# File 'lib/statsample/test/t.rb', line 75

def tails
  @tails
end

#u ⇒ Object

Population mean to contrast



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# File 'lib/statsample/test/t.rb', line 67

def u
  @u
end

Instance Method Details

#compute ⇒ Object

Set t and probability for given u



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# File 'lib/statsample/test/t.rb', line 93

def compute
  @t  = T.one_sample(@vector.mean, @u, @vector.sd, @vector.n_valid)
  @probability = p_using_cdf(Distribution::T.cdf(@t, @df), tails)
end

#report_building(b) ⇒ Object

:nodoc:



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# File 'lib/statsample/test/t.rb', line 102

def report_building(b) # :nodoc:
  b.section(:name=>@name) {|s|
    s.text "Sample mean: #{@vector.mean}"
    s.text "Population mean:#{u}"
    s.text "Tails: #{tails}"
    s.text sprintf("t = %0.4f, p=%0.4f, d.f=%d", t, probability, df)
  }
end

#summary ⇒ Object

Presents summary of analysis



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# File 'lib/statsample/test/t.rb', line 99

def summary
  ReportBuilder.new(:no_title=>true).add(self).to_text
end