Class: Statsample::Anova::TwoWayWithVectors

Inherits:
TwoWay show all
Defined in:
lib/statsample/anova/twoway.rb

Overview

Two Way Anova with vectors Example:

v1 = Daru::Vector.new([1,1,2,2])
v2 = Daru::Vector.new([1,2,1,2])
v3 = Daru::Vector.new([5,3,1,5])
anova=Statsample::Anova::TwoWayWithVectors.new(:a=>v1,:b=>v2, :dependent=>v3)

Instance Attribute Summary collapse

Attributes inherited from TwoWay

#df_a, #df_axb, #df_b, #df_total, #df_within, #f_a_object, #f_axb_object, #f_b_object, #ms_a, #ms_axb, #ms_b, #ms_total, #ms_within, #name, #name_a, #name_b, #name_within, #ss_a, #ss_axb, #ss_b, #ss_total, #ss_within

Instance Method Summary collapse

Methods inherited from TwoWay

#f_a, #f_a_probability, #f_axb, #f_axb_probability, #f_b, #f_b_probability, #report_building_table

Methods included from Summarizable

#summary

Constructor Details

#initialize(opts = Hash.new) ⇒ TwoWayWithVectors

For now, only equal sample cells allowed



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# File 'lib/statsample/anova/twoway.rb', line 122

def initialize(opts=Hash.new)
  raise "You should insert at least :a, :b and :dependent" unless  [:a, :b, :dependent].all? {|v| opts.has_key? v}
  @a_var   = :a
  @b_var   = :b
  @dep_var = :dependent
  @a_vector, @b_vector, @dep_vector = 
    Statsample.only_valid_clone opts[:a], opts[:b], opts[:dependent]
  
  ds  = Daru::DataFrame.new({@a_var=>@a_vector, @b_var=>@b_vector, @dep_var=>@dep_vector})
  @ds = ds.clone_only_valid
  _p  = @a_vector.factors.size
  _q  = @b_vector.factors.size
  @x_general = @dep_vector.mean
  @axb_means = {}
  @axb_sd    = {}
  @vectors   = []
  n=nil
  @ds.to_multiset_by_split(a_var,b_var).each_vector(dep_var) {|k,v|
    @axb_means[k] = v.mean
    @axb_sd[k]    = v.sd
    @vectors << v
    n ||= v.size
    raise "All cell sizes should be equal" if n!=v.size
  }

  @a_means={}
  @ds.to_multiset_by_split(a_var).each_vector(dep_var) {|k,v|
    @a_means[k]=v.mean
  }
  @b_means={}
  @ds.to_multiset_by_split(b_var).each_vector(dep_var) {|k,v|
    @b_means[k]=v.mean
  }
  ss_a = n*_q*@ds[a_var].factors.inject(0) {|ac,v|
    ac + (@a_means[v]-@x_general)**2
  }
  ss_b=n*_p*@ds[b_var].factors.inject(0) {|ac,v|
    ac+(@b_means[v]-@x_general)**2
  }
  ss_within = @ds.collect(:row) { |row|
    (row[dep_var]-@axb_means[[row[a_var],row[b_var]]])**2
  }.sum
  ss_axb = n*@axb_means.inject(0) {|ac,v|
    j,k=v[0]
    xjk=v[1]
    ac+(xjk-@a_means[j]-@b_means[k]+@x_general)**2
  }

  df_a=_p-1
  df_b=_q-1
  df_within=(_p*_q)*(n-1)
  
  opts_default={:name=>_("Anova Two-Way on %s") % @ds[dep_var].name, 
    :name_a=>@ds[a_var].name,
      :name_b=>@ds[b_var].name,
      :summary_descriptives=>true,
      :summary_levene=>false}
      
  @opts=opts_default.merge(opts).merge({:ss_a=>ss_a,:ss_b=>ss_b, :ss_axb=>ss_axb, :ss_within=>ss_within, :df_a=>df_a, :df_b=>df_b, :df_within=>df_within})
  
  
  super(@opts)
end

Instance Attribute Details

#a_var ⇒ Object (readonly)

Returns the value of attribute a_var.



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# File 'lib/statsample/anova/twoway.rb', line 120

def a_var
  @a_var
end

#b_var ⇒ Object (readonly)

Returns the value of attribute b_var.



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# File 'lib/statsample/anova/twoway.rb', line 120

def b_var
  @b_var
end

#dep_var ⇒ Object (readonly)

Returns the value of attribute dep_var.



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# File 'lib/statsample/anova/twoway.rb', line 120

def dep_var
  @dep_var
end

#summary_descriptives ⇒ Object

Show summary descriptives for variables (means)



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# File 'lib/statsample/anova/twoway.rb', line 119

def summary_descriptives
  @summary_descriptives
end

#summary_levene ⇒ Object

Show summary Levene test



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# File 'lib/statsample/anova/twoway.rb', line 117

def summary_levene
  @summary_levene
end

Instance Method Details

#levene ⇒ Object 



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# File 'lib/statsample/anova/twoway.rb', line 185

def levene
  Statsample::Test.levene(@vectors, :name=>_("Test of Homogeneity of variances (Levene)"))
end

#report_building(builder) ⇒ Object

:nodoc:#



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# File 'lib/statsample/anova/twoway.rb', line 188

def report_building(builder) #:nodoc:#
  builder.section(:name=>@name) do |s|
    if summary_descriptives
      s.table(:header =>['']+@ds[a_var].factors.map {|a| @ds[a_var].index_of(a)}+[_("%s Mean") % @name_b]) do |t|
        @ds[b_var].factors.each do |b|
          t.row([@ds[b_var].index_of(b)]+@ds[a_var].factors.map {|a| "%0.3f" % @axb_means[[a,b]] } + ["%0.3f" % @b_means[b]])
        end
        t.row([_("%s Mean") % @name_a]+@ds[a_var].factors.map {|a| "%0.3f" % @a_means[a]}+ ["%0.3f" % @x_general])
      end
    end
    if summary_levene
      s.parse_element(levene)
    end
    report_building_table(s)

  end
end