Method: Statsample::Reliability::ScaleAnalysis#item_characteristic_curve

Defined in:
lib/statsample/reliability/scaleanalysis.rb

#item_characteristic_curve ⇒ Object

Returns a hash with structure



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# File 'lib/statsample/reliability/scaleanalysis.rb', line 63

def item_characteristic_curve
  i=0
  out={}
  total={}
  @ds.each do |row|
    tot=@total[i]
    @ds.vectors.each do |f|
      out[f]||= {}
      total[f]||={}
      out[f][tot]||= 0
      total[f][tot]||=0
      out[f][tot]+= row[f]
      total[f][tot]+=1
    end
    i+=1
  end
  total.each do |f,var|
    var.each do |tot,v|
      out[f][tot]=out[f][tot].quo(total[f][tot])
    end
  end
  out
end