Method: Statsample::Reliability::ScaleAnalysis#stats_if_deleted_intern

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

#stats_if_deleted_intern ⇒ Object

:nodoc:


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# File 'lib/statsample/reliability/scaleanalysis.rb', line 131

def stats_if_deleted_intern # :nodoc:
  return Hash.new if @ds.ncols == 1
  vecs = @ds.vectors.to_a
  vecs.inject({}) do |a,v|
    cov_2=@cov_m.submatrix(vecs - [v])
    #ds2=@ds.clone
    #ds2.delete_vector(v)
    #total=ds2.vector_sum
    a[v]={}
    #a[v][:mean]=total.mean
    a[v][:mean]=@mean-item_statistics[v][:mean]
    a[v][:variance_sample]=cov_2.total_sum
    a[v][:sds]=Math::sqrt(a[v][:variance_sample])
    n=cov_2.row_size
    a[v][:alpha] = (n>=2) ? Statsample::Reliability.cronbach_alpha_from_covariance_matrix(cov_2) : nil
    a
  end
end