polychoric.rb in statsample-2.0.0

- old
+ new
@@ -1,27 +1,40 @@
 #!/usr/bin/ruby
 $:.unshift(File.dirname(__FILE__)+'/../lib/')
-$:.unshift("/home/cdx/usr/lib/statsample-bivariate-extension/lib/")
 
+# == Description
+# Polychoric Correlation using two-step and joint method
+#
+# Polychoric correlation in statsample requires installation of 
+# the [statsample-bivariate-extension](https://rubygems.org/gems/statsample-bivariate-extension) 
+# gem. This gem extends the Statsample::Bivariate class with useful 
+# algorithms for polychoric and tetrachoric correlation.
+# 
+# Statsample will automatically detect presence of polychoric/tetrachoric 
+# algorithms so there is no need to explicitly require the gem.
+# 
+# In this example we'll see how polychoric correlation can be 
+# performed using statsample.
 require 'statsample'
 Statsample::Analysis.store(Statsample::Bivariate::Polychoric) do 
-ct=Matrix[[rand(10)+50, rand(10)+50,  rand(10)+1],
-          [rand(20)+5,  rand(50)+4,   rand(10)+1],
-          [rand(8)+1,   rand(12)+1,   rand(10)+1]]
+  ct=Matrix[[rand(10)+50, rand(10)+50,  rand(10)+1],
+            [rand(20)+5,  rand(50)+4,   rand(10)+1],
+            [rand(8)+1,   rand(12)+1,   rand(10)+1]]
 
-# Estimation of polychoric correlation using two-step (default)
-poly=polychoric(ct, :name=>"Polychoric with two-step", :debug=>false)
-summary poly
+  # Estimation of polychoric correlation using two-step (default)
+  poly=polychoric(ct, :name=>"Polychoric with two-step", :debug=>false)
+  summary poly
 
-# Estimation of polychoric correlation using joint method (slow)
-poly=polychoric(ct, :method=>:joint, :name=>"Polychoric with joint")
-summary poly
+  # Estimation of polychoric correlation using joint method (slow)
+  poly=polychoric(ct, :method=>:joint, :name=>"Polychoric with joint")
+  summary poly
 
-# Uses polychoric series (not recomended)
+  # Uses polychoric series (not recomended)
 
-poly=polychoric(ct, :method=>:polychoric_series, :name=>"Polychoric with polychoric series")
-summary poly
+  poly=polychoric(ct, :method=>:polychoric_series, :name=>"Polychoric with polychoric series")
+  summary poly
 end
+
 if __FILE__==$0
    Statsample::Analysis.run_batch
 end
 