lib/statsample/reliability.rb in statsample-1.4.0 vs lib/statsample/reliability.rb in statsample-1.4.1

@@ -3,11 +3,10 @@
     class << self
       # Calculate Chonbach's alpha for a given dataset.
       # only uses tuples without missing data
       def cronbach_alpha(ods)
         ds=ods.dup_only_valid
-        return nil if ds.vectors.any? {|k,v| v.variance==0}
         n_items=ds.fields.size
         return nil if n_items<=1
         s2_items=ds.vectors.inject(0) {|ac,v|
         ac+v[1].variance }
         total=ds.vector_sum
@@ -148,6 +147,6 @@
 end # Statsample
 
 require 'statsample/reliability/icc.rb'
 require 'statsample/reliability/scaleanalysis.rb'
 require 'statsample/reliability/skillscaleanalysis.rb'
-require 'statsample/reliability/multiscaleanalysis.rb'
\ No newline at end of file
+require 'statsample/reliability/multiscaleanalysis.rb'