Provides advanced bivariate statistics:

• Tetrachoric correlation
• Polychoric correlation

• Statsample::Bivariate::Polychoric class provides polychoric correlation
• Statsample::Bivariate::Tetrachoric class provides tetrachoric correlation

require 'statsample'
a=40
b=10
c=20
d=30
tetra=Statsample::Bivariate::Tetrachoric.new(a,b,c,d)
puts tetra.summary

require 'statsample'
ct=Matrix[[58,52,1],[26,58,3],[8,12,9]]
poly=Statsample::Bivariate::Polychoric.new(ct)
puts poly.summary

• Statsample

This gem is a statsample dependency. If you want to install it separatly

• gem install statsample-bivariate-extension

BSD 2-Clause (see LICENSE.txt)