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Statsample::Crosstab

Class to create crosstab of data With this, you can create reports and do chi square test The first vector will be at rows and the second will the the columns

Attributes

v_rows[R]
v_cols[R]
row_label[RW]
column_label[RW]
name[RW]
percentage_row[RW]
percentage_column[RW]
percentage_total[RW]

Public Class Methods

new(v1, v2, opts=Hash.new) click to toggle source
# File lib/statsample/crosstab.rb, line 10
def initialize(v1, v2, opts=Hash.new)
  raise ArgumentError, "Both arguments should be Vectors" unless v1.is_a? Statsample::Vector and v2.is_a? Statsample::Vector
  raise ArgumentError, "Vectors should be the same size" unless v1.size==v2.size
  @v_rows, @v_cols=Statsample.only_valid_clone(v1,v2)
  @cases=@v_rows.size
  @row_label=v1.name
  @column_label=v2.name
  @name=nil
  @percentage_row = @percentage_column = @percentage_total=false
  opts.each{|k,v|
    self.send("#{k}=",v) if self.respond_to? k
  }
  @name||=_("Crosstab %s - %s") % [@row_label, @column_label]
end

Public Instance Methods

chi_square() click to toggle source

Chi square, based on expected and real matrix

# File lib/statsample/crosstab.rb, line 69
def chi_square
    require 'statsample/test'
    Statsample::Test.chi_square(self.to_matrix, matrix_expected)
end
cols_empty_hash() click to toggle source
# File lib/statsample/crosstab.rb, line 87
def cols_empty_hash
  cols_names.inject({}) {|a,x| a[x]=0;a}
end
cols_names() click to toggle source
# File lib/statsample/crosstab.rb, line 27
def cols_names
  @v_cols.factors.sort
end
cols_total() click to toggle source
# File lib/statsample/crosstab.rb, line 33
def cols_total
  @v_cols.frequencies
end
frequencies() click to toggle source
# File lib/statsample/crosstab.rb, line 37
def frequencies
  base=rows_names.inject([]){|s,row| 
    s+=cols_names.collect{|col| [row,col]}
  }.inject({}) {|s,par|
    s[par]=0
    s
  }
  base.update(Statsample::vector_cols_matrix(@v_rows,@v_cols).to_a.to_vector.frequencies)
end
frequencies_by_col() click to toggle source
# File lib/statsample/crosstab.rb, line 61
def frequencies_by_col
  f=frequencies
  cols_names.inject({}){|sc,col| 
    sc[col]=rows_names.inject({}) {|sr,row| sr[row]=f[[row,col]]; sr}
    sc
  }
end
frequencies_by_row() click to toggle source
# File lib/statsample/crosstab.rb, line 54
def frequencies_by_row
f=frequencies
rows_names.inject({}){|sr,row|
  sr[row]=cols_names.inject({}) {|sc,col| sc[col]=f[[row,col]]; sc}
  sr
}
end
matrix_expected() click to toggle source

Useful to obtain chi square

# File lib/statsample/crosstab.rb, line 74
def matrix_expected
  rn=rows_names
  cn=cols_names
  rt=rows_total
  ct=cols_total
  t=@v_rows.size
  m=rn.collect{|row|
    cn.collect{|col|
      (rt[row]*ct[col]).quo(t) 
      }
  }
  Matrix.rows(m)
end
report_building(builder) click to toggle source
# File lib/statsample/crosstab.rb, line 90
def report_building(builder)
  builder.section(:name=>@name) do |generator|
    fq=frequencies
    rn=rows_names
    cn=cols_names
    total=0
    total_cols=cols_empty_hash
    generator.text "Chi Square: #{chi_square}"
    generator.text(_("Rows: %s") % @row_label) unless @row_label.nil?
    generator.text(_("Columns: %s") % @column_label) unless @column_label.nil?
    
    t=ReportBuilder::Table.new(:name=>@name+" - "+_("Raw"), :header=>[""]+cols_names.collect {|c| @v_cols.labeling(c)}+[_("Total")])
    rn.each do |row|
      total_row=0
      t_row=[@v_rows.labeling(row)]
      cn.each do |col|
        data=fq[[row,col]]
        total_row+=fq[[row,col]]
        total+=fq[[row,col]]                    
        total_cols[col]+=fq[[row,col]]                    
        t_row.push(data)
      end
      t_row.push(total_row)
      t.row(t_row)
    end
    t.hr
    t_row=[_("Total")]
    cn.each do |v|
      t_row.push(total_cols[v])
    end
    t_row.push(total)
    t.row(t_row)
    generator.parse_element(t)
    
    if(@percentage_row)
      table_percentage(generator,:row)
    end
    if(@percentage_column)
    table_percentage(generator,:column)
    end
    if(@percentage_total)
    table_percentage(generator,:total)
    end
  end
end
rows_names() click to toggle source
# File lib/statsample/crosstab.rb, line 24
def rows_names
  @v_rows.factors.sort
end
rows_total() click to toggle source
# File lib/statsample/crosstab.rb, line 30
def rows_total
  @v_rows.frequencies
end
table_percentage(generator,type) click to toggle source
# File lib/statsample/crosstab.rb, line 138
def table_percentage(generator,type)
  fq=frequencies
  cn=cols_names
  rn=rows_names
  rt=rows_total
  ct=cols_total
  
  type_name=case type
    when :row     then  _("% Row")
    when :column  then  _("% Column")
    when :total   then  _("% Total")
  end
  
  t=ReportBuilder::Table.new(:name=>@name+" - "+_(type_name), :header=>[""]+cols_names.collect {|c| @v_cols.labeling(c) } + [_("Total")])
    rn.each do |row|
      t_row=[@v_rows.labeling(row)]
      cn.each do |col|
        total=case type
          when :row     then  rt[row]
          when :column  then  ct[col]
          when :total   then  @cases
        end
        data = sprintf("%0.2f%%", fq[[row,col]]*100.0/ total )
        t_row.push(data)
      end
      total=case type
        when :row     then  rt[row]
        when :column  then  @cases
        when :total   then  @cases
      end              
      t_row.push(sprintf("%0.2f%%", rt[row]*100.0/total))
      t.row(t_row)
    end
    
    t.hr
    t_row=[_("Total")]
    cn.each{|col|
      total=case type
        when :row     then  @cases
        when :column  then  ct[col]
        when :total   then  @cases
      end
      t_row.push(sprintf("%0.2f%%", ct[col]*100.0/total))
    }
  t_row.push("100%")
  t.row(t_row)
  generator.parse_element(t)
end
to_matrix() click to toggle source
# File lib/statsample/crosstab.rb, line 46
def to_matrix
  f=frequencies
  rn=rows_names
  cn=cols_names
  Matrix.rows(rn.collect{|row|
      cn.collect{|col| f[[row,col]]}
  })
end

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