Pitometer log

In statistics, a concordant pair is a pair of a two-variable (bivariate) observation data-set {X₁,Y₁} and {X₂,Y₂}, where:

$\mathrm{sgn}(X_2-X_1)=\mathrm{sgn}(Y_2-Y_1)$

Correspondingly, a discordant pair is a pair, as defined above, where

$\mathrm{sgn}(X_2-X_1)=-\mathrm{sgn}(Y_2-Y_1)$

and the sign function, often represented as sgn, is defined as:

$\mathrm{sgn}x=\{\begin{array}{ccc}-1& :& x<0\\ 0& :& x=0\\ 1& :& x>0\end{array}$

See also

• Kendall tau distance
• Spearman's rank correlation coefficient
• Rank correlation
• sign function

References

• Kendall rank correlation.
• Kendall, M. (1948) Rank Correlation Methods, Charles Griffin & Company Limited
• Kendall, M. (1938) "A New Measure of Rank Correlation", Biometrica, 30, 81-89.

External links

• MacTutor: David George Kendall
• Janus: The Papers of Professor David Kendall