Measure to compare true observed response with predicted response in regression tasks.
Usage
ktau(truth, response, ...)
Value
Performance value as numeric(1).
Arguments
truth
(numeric())
True (observed) values.
Must have the same length as response.
response
(numeric())
Predicted response values.
Must have the same length as truth.
...
(any)
Additional arguments. Currently ignored.
Meta Information
Type: "regr"
Range: \([-1, 1]\)
Minimize: FALSE
Required prediction: response
Details
Kendall's tau is defined as Kendall's rank correlation coefficient between truth and response.
It is defined as $$
\tau = \frac{(\mathrm{number of concordant pairs)} - (\mathrm{number of discordant pairs)}}{\mathrm{(number of pairs)}}
$$
Calls stats::cor() with method set to "kendall".
References
Rosset S, Perlich C, Zadrozny B (2006).
“Ranking-based evaluation of regression models.”
Knowledge and Information Systems, 12(3), 331--353.
tools:::Rd_expr_doi("10.1007/s10115-006-0037-3").