mlr3measures (version 0.3.1)

mcc: Matthews Correlation Coefficient

Description

Binary classification measure defined as $$ \frac{\mathrm{TP} \cdot \mathrm{TN} - \mathrm{FP} \cdot \mathrm{FN}}{\sqrt{(\mathrm{TP} + \mathrm{FP}) (\mathrm{TP} + \mathrm{FN}) (\mathrm{TN} + \mathrm{FP}) (\mathrm{TN} + \mathrm{FN})}}. $$

Usage

mcc(truth, response, positive, ...)

Arguments

truth

(factor()) True (observed) labels. Must have the exactly same two levels and the same length as response.

response

(factor()) Predicted response labels. Must have the exactly same two levels and the same length as truth.

positive

(character(1)) Name of the positive class.

...

(any) Additional arguments. Currently ignored.

Value

Performance value as numeric(1).

Meta Information

• Type: "binary"

• Range: \([-1, 1]\)

• Minimize: FALSE

• Required prediction: response

References

Matthews BW (1975). “Comparison of the predicted and observed secondary structure of T4 phage lysozyme.” Biochimica et Biophysica Acta (BBA) - Protein Structure, 405(2), 442--451. 10.1016/0005-2795(75)90109-9.

See Also

Other Binary Classification Measures: auc(), bbrier(), dor(), fbeta(), fdr(), fnr(), fn(), fomr(), fpr(), fp(), npv(), ppv(), prauc(), tnr(), tn(), tpr(), tp()

Examples

# NOT RUN {
set.seed(1)
lvls = c("a", "b")
truth = factor(sample(lvls, 10, replace = TRUE), levels = lvls)
response = factor(sample(lvls, 10, replace = TRUE), levels = lvls)
mcc(truth, response, positive = "a")
# }